systematic review dissertation structure

How to Write a Systematic Review Dissertation: With Examples

Writing a systematic review dissertation isn’t easy because you must follow a thorough and accurate scientific process. You must be an expert in research methodology to synthesise studies. In this article, I will provide a step-by-step approach to writing a top-notch systematic review dissertation.

Table of Contents

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As an Undergraduate or Master’s student, you’re are allowed to pick a systematic review for your dissertation. As a PhD student, you can use a systematic review methodology in the second chapter (literature review) of your dissertation. A systematic review is considered the highest level of empirical evidence, especially in clinical sciences like nursing and medicine. When developing new practice guidelines, new services, or new products, systematic reviews are searched and synthesised first on that topic or idea.

Factors to Consider When Writing a Systematic Review Dissertation

The nature of your research topic or research question.

Some research topics or questions strictly conform to qualitative or quantitative methods. For example, if you’re exploring the lived experiences, attitudes, perceptions, and meaning-making in a given population, you’ll need qualitative methods. However, you will require quantitative methods if looking into quantifiable variables like happiness, depression, academic performance, sleep, etc. That said, the nature of your research question should guide you. If your topic is qualitative, you’ll need qualitative studies only. If your topic is quantitative, you’ll need quantitative studies only. Systematic reviews of qualitative studies are less intricate than of quantitative studies. Still, they require a thoughtful approach in synthesizing findings from various qualitative studies.

If you choose to review quantitative studies, you might need to conduct a meta-analysis in your systematic review. A meta-analysis refers to statistical techniques used in pooling findings from various independent studies to compute a summary statistic. For example, in your dissertation, you may aim to investigate the effect of a student well-being programme embedded in university classes on the happiness of university students. Various studies that have investigated the same or a related intervention and quantitively measured happiness among university students must be synthesised together using a statistical technique. The ultimate outcome of that meta-analysis is to provide an overview of the overall trend of the effect of the intervention on university student’s happiness. For more information about how to formulate a research question for a systematic review with a meta-analysis, visit this link.

An example meta-analysis showing the statistical combination of findings from various studies to indicate the overall effect of a psychological intervention on the psychological well-being of university students.

Availability of primary studies

Finding primary studies for your systematic review is the hardest thing you can encounter with this approach. You can choose your topic and plan your journey so well. Upon reaching the point you need primary studies to answer your research question, you get stuck. Retrieving primary studies is challenging because it requires advanced search strategies on various online databases. Doing an advanced search strategy can be an uphill task for someone who has never done a systematic review. This is because, more often than not, depending on the topic, primary studies are not readily available on the Internet. Remember, secondary studies, like systematic reviews and literature reviews, are not eligible for systematic reviews.

Supervisor’s recommendation

Always confirm with your supervisor if you can do a systematic review dissertation. Some supervisors may feel it better for you to do a primary study. So, always confirm with your supervisor before doing much.

Your confidence

Always ensure you’re confident that you can do a systematic review on your own. Writing a systematic review isn’t easy. You need to be aware that doing a systematic review may even be harder than doing interviews or surveys in primary research. Why? A systematic review involves combining many primary studies together in a scientific manner. That means you must have expertise in various research methodologies to know the best way to integrate or synthesise the various studies.

Availability of time and resources

The main advantage of doing a systematic review dissertation is that it saves a lot of time. Conducting interviews or surveys can be time- and resource-consuming. However, with a systematic review, you do everything from your desk. It will save you a lot of time and resources. If you find that you meet many of the requirements of successfully conducting a systematic review, the next step is to engage in the actual process. The step-by-step approach used in writing systematic reviews is outlined below.

Step-by-Step Process in Writing a Systematic Review Dissertation

The following steps are iterative, meaning you can start over again and again until you meet your research objectives. The step-by-step guide on how to write a systematic review dissertation is summarized in the infographic shown below.

Step-by-step guide on how to write a systematic review dissertation

Step 1: Formulate the systematic review research question

The starting point of a systematic review is to formulate a research question. As stated above, the nature of your research question will help you make key decisions. For example, you will be able to know which design (quantitative versus qualitative) to consider in your inclusion and exclusion criteria.

Step 2: Do a preliminary search

The next step is to perform a preliminary search on the Internet to determine if another systematic review has been published. It is not acceptable to repeat what has already been done. Your research should be novel and contribute to a knowledge gap. However, if you find that another systematic review has already been published on your topic. You should consider the publication date.

In most cases, systematic reviews on given topics are outdated. They have not used recent studies published on that topic, thus missing important updates. That can be a good reason you’re conducting your study. Suppose there’s an updated systematic review on your topic. In that case, you should consider reformulating your research question to address a specific knowledge gap.

Step 3: Develop your systematic review inclusion and exclusion criteria

One unique thing about systematic reviews is that they must be based on a very specific population, intervention/exposure, and assess a specific outcome. Let’s say, for example, you write on Intervention A’s effectiveness in reducing depression symptoms in older frail people. In that case, you must retrieve studies that strictly assess the effectiveness of Intervention A, the outcome being depression symptoms and the population being older frail people.

Therefore, it will be against the principles of a systematic review to focus on Intervention B (different intervention/exposure) on anxiety (different outcomes) in younger people (different populations). Also, depending on your research question, you will need to determine the research design (qualitative versus quantitative) of the studies you will review. Other criteria to consider are the country of publication, the publication date, language, etc.

Step 4: Develop your systematic review search strategy

As said, the main challenge in writing a systematic review is to identify papers. Your literature search should be thorough so that you don’t leave out some relevant studies. Developing a literature search strategy isn’t easy because you must start identifying relevant keywords and search terms for your topic. You must start by knowing common terminologies used in your subject of interest.

Afterward, combine the keywords using Boolean connectors like “AND” & “OR.” For example, suppose my topic is the effectiveness of cognitive behavioural therapy in treating anxiety in adolescents. In that regard, I can combine my keywords as follows: (Cognitive behavioural therapy OR CBT) AND (anxiety) AND (adolescents OR youth). If you use terminologies unknown in your discipline, you will likely not find relevant studies for review.

Step 5: Plan and perform systematic review database selection

At this stage, you identify the databases you’ll use to execute your search strategy. When writing a systematic review dissertation, you also need to report the databases that you searched. Commonly searched ones in the field of social and health sciences include PubMed, Google Scholar, Cochrane, PsycInfo, and many others. You need to know how each database works. Also, apart from Google Scholar and PubMed, most of these databases require paid or institutional access. Liaise with your supervisor or librarian to help in identifying good databases for subject and discipline.

Step 6: Perform systematic review screening using titles and abstracts

When you execute your search strategy on each database, results or search hits will be displayed. This is also another difficult step because of tedious work involved. You start by screening the titles. Then, eliminate results that contain irrelevant titles. You need to be careful at this point because sometimes people eliminate even relevant studies. The title doesn’t need to contain exactly your keywords. Some titles appear totally irrelevant but they actually contain useful data inside.

After screening titles, the next step is to screen abstracts. You may be surprised at this point that the titles you thought were irrelevant actually contain relevant information. For instance, some studies may indicate in the title that their study focused on depression as an outcome when you’re interested in anxiety. However, reading the abstract may surprise you that depression was only a primary outcome. The authors also measured secondary outcomes, among them anxiety. In such an article, you can decide to focus on anxiety results only because they are relevant to your study.

Step 7: Do a manual search to supplement database search

After screening articles identified using various databases, the next step is to augment the search strategy with a manual search. This will ensure you don’t miss relevant studies in your systematic review dissertation. The manual search involves identifying more studies in the bibliographies of the identified articles using a database search. It is also about contacting the authors and experts sourced from the found articles to give access to more articles that may not be found online. Finally, you can also identify key journals from the articles and perform a hand search. For example, suppose I identify the Journal of Cognitive Psychology. In that case, I will visit that journal’s website and perform a manual search there. A properly done manual search can help you identify more articles that you couldn’t have identified using databases only.

Step 8: Perform systematic review screening using the full-body texts

After having all your articles intact, the next step is to screen for full-text bodies. In most cases, the titles and abstracts may not contain enough information for screening purposes. You must read the full texts of the articles to determine their full eligibility. At this point, you screen articles identified through database search and manual search altogether. For example, sometimes you may be interested in healthy adolescents. In the abstract, the author of the articles may only report adolescents without providing any specifics about them. Upon reading the full text, you may discover that the authors included adolescents with mental issues that are not within your study’s scope. Therefore, always do a full-text screening before you move to the next step.

Step 9: Perform systematic review quality assessment using PRISMA, etc

Systematic review dissertations can be used to inform the formulation of practice guidelines and even inform policies. You must strive to review only studies with rigorous methodological quality. The quality assessment tool will depend on your study’s design. The commonly used ones for student dissertations include CASP Checklists and Joanna Briggs Institute (JBI) Checklists. You can consult with your supervisor before arriving at the final decision. Transparently report your quality assessment findings. For example, indicate the score of each study under each item of each tool and calculate the overall score in the form of a percentage. Also, always have a cut-off of 65%, and studies whose methodological rigour is below the cut-off are excluded.

Step 10: Perform systematic review data extraction

The next step is to extract relevant data from your studies. Your data extraction approach depends on the research design of the studies you used. If you use qualitative studies, your data extraction can focus on individual studies’ findings, particularly themes. You can also extract data that can aid in-depth analysis, such as country of study, population characteristics, etc. Using quantitative studies, you can collect quantitative data that will aid your analysis, such as means and standard deviations and other crucial information relevant to your analysis technique. Always chart your data in a tabular format to facilitate easy management and handling.

Step 11: Carry on with systematic review data analysis

The data analysis approach used in your systematic review dissertation will depend on the research design. Using qualitative studies, you will rely on qualitative approaches to analyse your data. For example, you can do a thematic analysis or a narrative synthesis. If you used quantitative studies, you might need to perform a meta-analysis or narrative synthesis. A meta-analysis is done when you have homogenous studies (such as population, outcome variables, measurement tools, etc.) that are experimental in nature. Particularly, meta-analysis is performed when reviewing controlled randomized trials or other interventional studies. In other words, meta-analysis is appropriately used when reviewing the effectiveness of interventions. However, if your quantitative studies are heterogenous, such as using different research designs, you must perform a narrative synthesis.

Step 12: Prepare the written report

The final step is to produce a written report of your systematic review dissertation. One of the ethical concerns in systematic reviews is transparency. You can improve the transparency of your reporting by using an established protocol like PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses).

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Teaching and Research guides

Systematic reviews.

• Starting the review
• About systematic reviews
• Research question
• Plan your search
• Sources to search
• Search example
• Screen and analyse

What to include

Introduction, discussion and conclusion.

• Guides and software
• Further help

In general, the writing process for a systematic review is similar to the process of writing any other kind of review.

A systematic review should provide an answer to the research question , it is not a broad overview of current trends and gaps in research. The review should show the reader how the answer was found, and provide the results you have identified.

A systematic review must have a detailed methodology that describes the search process and the selection process. This is why careful documentation of the methodology is important. A reader of the review should be able to critically interpret the findings- to understand why sources were chosen, how they were assessed, and how conclusions were reached.

The structure of the systematic review differs from the narrative review or the traditional literature review that allows you to organise it to best support your argument. A systematic review should reflect the stages outlined in the protocol . With a systematic review reporting guidelines should be followed that help you identify what should be included in each section of the review. One such standard approach is PRISMA .

Although much time is invested in developing a search strategy and screening results, a systematic review is valued by the critical reflection and interpretation of the findings . Focus on analysing, not summarising. Use a critical analysis tool to assess the studies.

Your systematic review needs to tell a story, and it needs to clearly articulate how it provides meaningful and original advancement of the field .

The abstract provides an overview of the systematic review. It usually covers the following:

• A brief background (what we know and often the gap that the review will fill)
• The aim or hypothesis
• Summary of methods
• Summary of results
• Summary of conclusion (and sometimes recommendations).

Note that these points represent the general ‘story line’ seen in most systematic reviews: What we know (and perhaps what the gap is); what we set out to do; what we did; what we found; what this means.

The introduction provides an overview of the systematic review and enough contextual information for the reader to make sense of the remainder of the report. It usually covers the following:

• Background information to contextualise the review (what we already know about this area)
• Definitions of key terms and concepts if needed
• The rationale for the study (often in terms of a gap in knowledge that needs to be filled, a lack of agreement within the literature that needs to be resolved, or the potential implications of the findings)
• The aims and/or objectives (optional)
• The research question/s emanating from the rationale
• Additional information (Optional)

Note however, that these points are not always in this order. Some writers prefer to begin with the research questions, followed by the context, building to the rationale.

The  methods  section can be divided up into two main sections.

The first section describes how the literature search was conducted. This section may contain any of the following information: 

• The databases searched and whether any manual searches were completed 
• How search terms were identified 
• What terms were employed in the key word searches 
• If particular sections of articles were looked at during the search and collection stage i.e. titles, abstracts, table of contents ( note : the information in these sections may have informed the selection process) 

The second  section discusses the criteria for including or excluding studies. This section may include any of the following information:

• Your selection criteria
• How you identified relevant studies for further analysis 
• What articles you reviewed 
• What particular areas you looked at in the selected articles i.e. a relationship or association between two things (such as a genetic predisposition and a drug), the outcome measures of a health campaign, drug treatment, or clinical intervention, the differing impact of a particular drug or treatment. 

Details about the kind of systematic review undertaken, i.e. thematic analysis, might also be mentioned in the methods section.​

Broadly speaking, in the  results  section,  everything you have done so far needs to be presented.  This can include any of the following: ​

• briefly mention the  databases used for the searching
• identify the number of hits
• show how the articles were selected by title, abstract, table of contents or other procedures. 
• Overview of the kinds of studies selected for the review i.e. the types of methodologies or study designs used.
• where the trials were conducted
• treatment  duration
• details about participants
• similarities and differences in the way data was measured
• similar or different approaches to the same treatment or condition 
• Risk of bias across studies 
• the kinds of relationships or associations demonstrated by the studies
• frequency of positive or adverse effects of a particular treatment or drug
• the number of studies that found a positive correlation between two phenomena or found a causal relationship between two variables

Often, researchers will include tables in the Results section or Appendix to provide on overview of data found in the studies. Remember, tables in the Results section need to be explained fully.

A primary function of your discussion and conclusion is to help readers understand the main findings and implications of the review.

The following elements are commonly found in the discussion and conclusion sections. Note that the points listed are neither mandatory nor in any prescribed order.   

Discussion:

• Summary of main findings
• Interpretation of main findings (don’t repeat results)
• Strengths and weaknesses
• Comparison with previous review findings or general literature
• The degree to which the review answers the research question
• Whether the hypothesis was confirmed
• Limitations (e.g. biases, lack of methodological rigour or weak evidence in the articles)

Conclusion:

• Summary of how it answers the research question (the ‘take home’ message)
• Significance of the findings
• Reminder of the limitations
• Implications and recommendations for further research.

Separate or combined?

A key difference between a discussion and a conclusion relates to how specific or general the observations are. A discussion closely interprets results in the context of the review. A conclusion identifies the significance and the implications beyond the review. Some reviews present these as separately headed sections. Many reviews, however, present only one section using a combination of elements. This section may be headed either Discussion or Conclusion.

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• Systematic Review | Definition, Examples & Guide

Systematic Review | Definition, Examples & Guide

Published on 15 June 2022 by Shaun Turney . Revised on 17 October 2022.

A systematic review is a type of review that uses repeatable methods to find, select, and synthesise all available evidence. It answers a clearly formulated research question and explicitly states the methods used to arrive at the answer.

They answered the question ‘What is the effectiveness of probiotics in reducing eczema symptoms and improving quality of life in patients with eczema?’

In this context, a probiotic is a health product that contains live microorganisms and is taken by mouth. Eczema is a common skin condition that causes red, itchy skin.

Table of contents

What is a systematic review, systematic review vs meta-analysis, systematic review vs literature review, systematic review vs scoping review, when to conduct a systematic review, pros and cons of systematic reviews, step-by-step example of a systematic review, frequently asked questions about systematic reviews.

A review is an overview of the research that’s already been completed on a topic.

What makes a systematic review different from other types of reviews is that the research methods are designed to reduce research bias . The methods are repeatable , and the approach is formal and systematic:

• Formulate a research question
• Develop a protocol
• Search for all relevant studies
• Apply the selection criteria
• Extract the data
• Synthesise the data
• Write and publish a report

Although multiple sets of guidelines exist, the Cochrane Handbook for Systematic Reviews is among the most widely used. It provides detailed guidelines on how to complete each step of the systematic review process.

Systematic reviews are most commonly used in medical and public health research, but they can also be found in other disciplines.

Systematic reviews typically answer their research question by synthesising all available evidence and evaluating the quality of the evidence. Synthesising means bringing together different information to tell a single, cohesive story. The synthesis can be narrative ( qualitative ), quantitative , or both.

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Systematic reviews often quantitatively synthesise the evidence using a meta-analysis . A meta-analysis is a statistical analysis, not a type of review.

A meta-analysis is a technique to synthesise results from multiple studies. It’s a statistical analysis that combines the results of two or more studies, usually to estimate an effect size .

A literature review is a type of review that uses a less systematic and formal approach than a systematic review. Typically, an expert in a topic will qualitatively summarise and evaluate previous work, without using a formal, explicit method.

Although literature reviews are often less time-consuming and can be insightful or helpful, they have a higher risk of bias and are less transparent than systematic reviews.

Similar to a systematic review, a scoping review is a type of review that tries to minimise bias by using transparent and repeatable methods.

However, a scoping review isn’t a type of systematic review. The most important difference is the goal: rather than answering a specific question, a scoping review explores a topic. The researcher tries to identify the main concepts, theories, and evidence, as well as gaps in the current research.

Sometimes scoping reviews are an exploratory preparation step for a systematic review, and sometimes they are a standalone project.

A systematic review is a good choice of review if you want to answer a question about the effectiveness of an intervention , such as a medical treatment.

To conduct a systematic review, you’ll need the following:

• A precise question , usually about the effectiveness of an intervention. The question needs to be about a topic that’s previously been studied by multiple researchers. If there’s no previous research, there’s nothing to review.
• If you’re doing a systematic review on your own (e.g., for a research paper or thesis), you should take appropriate measures to ensure the validity and reliability of your research.
• Access to databases and journal archives. Often, your educational institution provides you with access.
• Time. A professional systematic review is a time-consuming process: it will take the lead author about six months of full-time work. If you’re a student, you should narrow the scope of your systematic review and stick to a tight schedule.
• Bibliographic, word-processing, spreadsheet, and statistical software . For example, you could use EndNote, Microsoft Word, Excel, and SPSS.

A systematic review has many pros .

• They minimise research b ias by considering all available evidence and evaluating each study for bias.
• Their methods are transparent , so they can be scrutinised by others.
• They’re thorough : they summarise all available evidence.
• They can be replicated and updated by others.

Systematic reviews also have a few cons .

• They’re time-consuming .
• They’re narrow in scope : they only answer the precise research question.

The 7 steps for conducting a systematic review are explained with an example.

Step 1: Formulate a research question

Formulating the research question is probably the most important step of a systematic review. A clear research question will:

• Allow you to more effectively communicate your research to other researchers and practitioners
• Guide your decisions as you plan and conduct your systematic review

A good research question for a systematic review has four components, which you can remember with the acronym PICO :

• Population(s) or problem(s)
• Intervention(s)
• Comparison(s)

You can rearrange these four components to write your research question:

• What is the effectiveness of I versus C for O in P ?

Sometimes, you may want to include a fourth component, the type of study design . In this case, the acronym is PICOT .

• Type of study design(s)
• The population of patients with eczema
• The intervention of probiotics
• In comparison to no treatment, placebo , or non-probiotic treatment
• The outcome of changes in participant-, parent-, and doctor-rated symptoms of eczema and quality of life
• Randomised control trials, a type of study design

Their research question was:

• What is the effectiveness of probiotics versus no treatment, a placebo, or a non-probiotic treatment for reducing eczema symptoms and improving quality of life in patients with eczema?

Step 2: Develop a protocol

A protocol is a document that contains your research plan for the systematic review. This is an important step because having a plan allows you to work more efficiently and reduces bias.

Your protocol should include the following components:

• Background information : Provide the context of the research question, including why it’s important.
• Research objective(s) : Rephrase your research question as an objective.
• Selection criteria: State how you’ll decide which studies to include or exclude from your review.
• Search strategy: Discuss your plan for finding studies.
• Analysis: Explain what information you’ll collect from the studies and how you’ll synthesise the data.

If you’re a professional seeking to publish your review, it’s a good idea to bring together an advisory committee . This is a group of about six people who have experience in the topic you’re researching. They can help you make decisions about your protocol.

It’s highly recommended to register your protocol. Registering your protocol means submitting it to a database such as PROSPERO or ClinicalTrials.gov .

Step 3: Search for all relevant studies

Searching for relevant studies is the most time-consuming step of a systematic review.

To reduce bias, it’s important to search for relevant studies very thoroughly. Your strategy will depend on your field and your research question, but sources generally fall into these four categories:

• Databases: Search multiple databases of peer-reviewed literature, such as PubMed or Scopus . Think carefully about how to phrase your search terms and include multiple synonyms of each word. Use Boolean operators if relevant.
• Handsearching: In addition to searching the primary sources using databases, you’ll also need to search manually. One strategy is to scan relevant journals or conference proceedings. Another strategy is to scan the reference lists of relevant studies.
• Grey literature: Grey literature includes documents produced by governments, universities, and other institutions that aren’t published by traditional publishers. Graduate student theses are an important type of grey literature, which you can search using the Networked Digital Library of Theses and Dissertations (NDLTD) . In medicine, clinical trial registries are another important type of grey literature.
• Experts: Contact experts in the field to ask if they have unpublished studies that should be included in your review.

At this stage of your review, you won’t read the articles yet. Simply save any potentially relevant citations using bibliographic software, such as Scribbr’s APA or MLA Generator .

• Databases: EMBASE, PsycINFO, AMED, LILACS, and ISI Web of Science
• Handsearch: Conference proceedings and reference lists of articles
• Grey literature: The Cochrane Library, the metaRegister of Controlled Trials, and the Ongoing Skin Trials Register
• Experts: Authors of unpublished registered trials, pharmaceutical companies, and manufacturers of probiotics

Step 4: Apply the selection criteria

Applying the selection criteria is a three-person job. Two of you will independently read the studies and decide which to include in your review based on the selection criteria you established in your protocol . The third person’s job is to break any ties.

To increase inter-rater reliability , ensure that everyone thoroughly understands the selection criteria before you begin.

If you’re writing a systematic review as a student for an assignment, you might not have a team. In this case, you’ll have to apply the selection criteria on your own; you can mention this as a limitation in your paper’s discussion.

You should apply the selection criteria in two phases:

• Based on the titles and abstracts : Decide whether each article potentially meets the selection criteria based on the information provided in the abstracts.
• Based on the full texts: Download the articles that weren’t excluded during the first phase. If an article isn’t available online or through your library, you may need to contact the authors to ask for a copy. Read the articles and decide which articles meet the selection criteria.

It’s very important to keep a meticulous record of why you included or excluded each article. When the selection process is complete, you can summarise what you did using a PRISMA flow diagram .

Next, Boyle and colleagues found the full texts for each of the remaining studies. Boyle and Tang read through the articles to decide if any more studies needed to be excluded based on the selection criteria.

When Boyle and Tang disagreed about whether a study should be excluded, they discussed it with Varigos until the three researchers came to an agreement.

Step 5: Extract the data

Extracting the data means collecting information from the selected studies in a systematic way. There are two types of information you need to collect from each study:

• Information about the study’s methods and results . The exact information will depend on your research question, but it might include the year, study design , sample size, context, research findings , and conclusions. If any data are missing, you’ll need to contact the study’s authors.
• Your judgement of the quality of the evidence, including risk of bias .

You should collect this information using forms. You can find sample forms in The Registry of Methods and Tools for Evidence-Informed Decision Making and the Grading of Recommendations, Assessment, Development and Evaluations Working Group .

Extracting the data is also a three-person job. Two people should do this step independently, and the third person will resolve any disagreements.

They also collected data about possible sources of bias, such as how the study participants were randomised into the control and treatment groups.

Step 6: Synthesise the data

Synthesising the data means bringing together the information you collected into a single, cohesive story. There are two main approaches to synthesising the data:

• Narrative ( qualitative ): Summarise the information in words. You’ll need to discuss the studies and assess their overall quality.
• Quantitative : Use statistical methods to summarise and compare data from different studies. The most common quantitative approach is a meta-analysis , which allows you to combine results from multiple studies into a summary result.

Generally, you should use both approaches together whenever possible. If you don’t have enough data, or the data from different studies aren’t comparable, then you can take just a narrative approach. However, you should justify why a quantitative approach wasn’t possible.

Boyle and colleagues also divided the studies into subgroups, such as studies about babies, children, and adults, and analysed the effect sizes within each group.

Step 7: Write and publish a report

The purpose of writing a systematic review article is to share the answer to your research question and explain how you arrived at this answer.

Your article should include the following sections:

• Abstract : A summary of the review
• Introduction : Including the rationale and objectives
• Methods : Including the selection criteria, search method, data extraction method, and synthesis method
• Results : Including results of the search and selection process, study characteristics, risk of bias in the studies, and synthesis results
• Discussion : Including interpretation of the results and limitations of the review
• Conclusion : The answer to your research question and implications for practice, policy, or research

To verify that your report includes everything it needs, you can use the PRISMA checklist .

Once your report is written, you can publish it in a systematic review database, such as the Cochrane Database of Systematic Reviews , and/or in a peer-reviewed journal.

A systematic review is secondary research because it uses existing research. You don’t collect new data yourself.

A literature review is a survey of scholarly sources (such as books, journal articles, and theses) related to a specific topic or research question .

It is often written as part of a dissertation , thesis, research paper , or proposal .

There are several reasons to conduct a literature review at the beginning of a research project:

• To familiarise yourself with the current state of knowledge on your topic
• To ensure that you’re not just repeating what others have already done
• To identify gaps in knowledge and unresolved problems that your research can address
• To develop your theoretical framework and methodology
• To provide an overview of the key findings and debates on the topic

Writing the literature review shows your reader how your work relates to existing research and what new insights it will contribute.

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Shaun Turney

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How to Do a Systematic Review: A Best Practice Guide for Conducting and Reporting Narrative Reviews, Meta-Analyses, and Meta-Syntheses

Affiliations.

• 1 Behavioural Science Centre, Stirling Management School, University of Stirling, Stirling FK9 4LA, United Kingdom; email: [email protected].
• 2 Department of Psychological and Behavioural Science, London School of Economics and Political Science, London WC2A 2AE, United Kingdom.
• 3 Department of Statistics, Northwestern University, Evanston, Illinois 60208, USA; email: [email protected].
• PMID: 30089228
• DOI: 10.1146/annurev-psych-010418-102803

Systematic reviews are characterized by a methodical and replicable methodology and presentation. They involve a comprehensive search to locate all relevant published and unpublished work on a subject; a systematic integration of search results; and a critique of the extent, nature, and quality of evidence in relation to a particular research question. The best reviews synthesize studies to draw broad theoretical conclusions about what a literature means, linking theory to evidence and evidence to theory. This guide describes how to plan, conduct, organize, and present a systematic review of quantitative (meta-analysis) or qualitative (narrative review, meta-synthesis) information. We outline core standards and principles and describe commonly encountered problems. Although this guide targets psychological scientists, its high level of abstraction makes it potentially relevant to any subject area or discipline. We argue that systematic reviews are a key methodology for clarifying whether and how research findings replicate and for explaining possible inconsistencies, and we call for researchers to conduct systematic reviews to help elucidate whether there is a replication crisis.

Keywords: evidence; guide; meta-analysis; meta-synthesis; narrative; systematic review; theory.

• Guidelines as Topic
• Meta-Analysis as Topic*
• Publication Bias
• Review Literature as Topic
• Systematic Reviews as Topic*

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An overview of methodological approaches in systematic reviews

Prabhakar veginadu.

1 Department of Rural Clinical Sciences, La Trobe Rural Health School, La Trobe University, Bendigo Victoria, Australia

Hanny Calache

2 Lincoln International Institute for Rural Health, University of Lincoln, Brayford Pool, Lincoln UK

Akshaya Pandian

3 Department of Orthodontics, Saveetha Dental College, Chennai Tamil Nadu, India

Mohd Masood

Associated data.

APPENDIX B: List of excluded studies with detailed reasons for exclusion

APPENDIX C: Quality assessment of included reviews using AMSTAR 2

The aim of this overview is to identify and collate evidence from existing published systematic review (SR) articles evaluating various methodological approaches used at each stage of an SR.

The search was conducted in five electronic databases from inception to November 2020 and updated in February 2022: MEDLINE, Embase, Web of Science Core Collection, Cochrane Database of Systematic Reviews, and APA PsycINFO. Title and abstract screening were performed in two stages by one reviewer, supported by a second reviewer. Full‐text screening, data extraction, and quality appraisal were performed by two reviewers independently. The quality of the included SRs was assessed using the AMSTAR 2 checklist.

The search retrieved 41,556 unique citations, of which 9 SRs were deemed eligible for inclusion in final synthesis. Included SRs evaluated 24 unique methodological approaches used for defining the review scope and eligibility, literature search, screening, data extraction, and quality appraisal in the SR process. Limited evidence supports the following (a) searching multiple resources (electronic databases, handsearching, and reference lists) to identify relevant literature; (b) excluding non‐English, gray, and unpublished literature, and (c) use of text‐mining approaches during title and abstract screening.

The overview identified limited SR‐level evidence on various methodological approaches currently employed during five of the seven fundamental steps in the SR process, as well as some methodological modifications currently used in expedited SRs. Overall, findings of this overview highlight the dearth of published SRs focused on SR methodologies and this warrants future work in this area.

1. INTRODUCTION

Evidence synthesis is a prerequisite for knowledge translation. 1 A well conducted systematic review (SR), often in conjunction with meta‐analyses (MA) when appropriate, is considered the “gold standard” of methods for synthesizing evidence related to a topic of interest. 2 The central strength of an SR is the transparency of the methods used to systematically search, appraise, and synthesize the available evidence. 3 Several guidelines, developed by various organizations, are available for the conduct of an SR; 4 , 5 , 6 , 7 among these, Cochrane is considered a pioneer in developing rigorous and highly structured methodology for the conduct of SRs. 8 The guidelines developed by these organizations outline seven fundamental steps required in SR process: defining the scope of the review and eligibility criteria, literature searching and retrieval, selecting eligible studies, extracting relevant data, assessing risk of bias (RoB) in included studies, synthesizing results, and assessing certainty of evidence (CoE) and presenting findings. 4 , 5 , 6 , 7

The methodological rigor involved in an SR can require a significant amount of time and resource, which may not always be available. 9 As a result, there has been a proliferation of modifications made to the traditional SR process, such as refining, shortening, bypassing, or omitting one or more steps, 10 , 11 for example, limits on the number and type of databases searched, limits on publication date, language, and types of studies included, and limiting to one reviewer for screening and selection of studies, as opposed to two or more reviewers. 10 , 11 These methodological modifications are made to accommodate the needs of and resource constraints of the reviewers and stakeholders (e.g., organizations, policymakers, health care professionals, and other knowledge users). While such modifications are considered time and resource efficient, they may introduce bias in the review process reducing their usefulness. 5

Substantial research has been conducted examining various approaches used in the standardized SR methodology and their impact on the validity of SR results. There are a number of published reviews examining the approaches or modifications corresponding to single 12 , 13 or multiple steps 14 involved in an SR. However, there is yet to be a comprehensive summary of the SR‐level evidence for all the seven fundamental steps in an SR. Such a holistic evidence synthesis will provide an empirical basis to confirm the validity of current accepted practices in the conduct of SRs. Furthermore, sometimes there is a balance that needs to be achieved between the resource availability and the need to synthesize the evidence in the best way possible, given the constraints. This evidence base will also inform the choice of modifications to be made to the SR methods, as well as the potential impact of these modifications on the SR results. An overview is considered the choice of approach for summarizing existing evidence on a broad topic, directing the reader to evidence, or highlighting the gaps in evidence, where the evidence is derived exclusively from SRs. 15 Therefore, for this review, an overview approach was used to (a) identify and collate evidence from existing published SR articles evaluating various methodological approaches employed in each of the seven fundamental steps of an SR and (b) highlight both the gaps in the current research and the potential areas for future research on the methods employed in SRs.

An a priori protocol was developed for this overview but was not registered with the International Prospective Register of Systematic Reviews (PROSPERO), as the review was primarily methodological in nature and did not meet PROSPERO eligibility criteria for registration. The protocol is available from the corresponding author upon reasonable request. This overview was conducted based on the guidelines for the conduct of overviews as outlined in The Cochrane Handbook. 15 Reporting followed the Preferred Reporting Items for Systematic reviews and Meta‐analyses (PRISMA) statement. 3

2.1. Eligibility criteria

Only published SRs, with or without associated MA, were included in this overview. We adopted the defining characteristics of SRs from The Cochrane Handbook. 5 According to The Cochrane Handbook, a review was considered systematic if it satisfied the following criteria: (a) clearly states the objectives and eligibility criteria for study inclusion; (b) provides reproducible methodology; (c) includes a systematic search to identify all eligible studies; (d) reports assessment of validity of findings of included studies (e.g., RoB assessment of the included studies); (e) systematically presents all the characteristics or findings of the included studies. 5 Reviews that did not meet all of the above criteria were not considered a SR for this study and were excluded. MA‐only articles were included if it was mentioned that the MA was based on an SR.

SRs and/or MA of primary studies evaluating methodological approaches used in defining review scope and study eligibility, literature search, study selection, data extraction, RoB assessment, data synthesis, and CoE assessment and reporting were included. The methodological approaches examined in these SRs and/or MA can also be related to the substeps or elements of these steps; for example, applying limits on date or type of publication are the elements of literature search. Included SRs examined or compared various aspects of a method or methods, and the associated factors, including but not limited to: precision or effectiveness; accuracy or reliability; impact on the SR and/or MA results; reproducibility of an SR steps or bias occurred; time and/or resource efficiency. SRs assessing the methodological quality of SRs (e.g., adherence to reporting guidelines), evaluating techniques for building search strategies or the use of specific database filters (e.g., use of Boolean operators or search filters for randomized controlled trials), examining various tools used for RoB or CoE assessment (e.g., ROBINS vs. Cochrane RoB tool), or evaluating statistical techniques used in meta‐analyses were excluded. 14

2.2. Search

The search for published SRs was performed on the following scientific databases initially from inception to third week of November 2020 and updated in the last week of February 2022: MEDLINE (via Ovid), Embase (via Ovid), Web of Science Core Collection, Cochrane Database of Systematic Reviews, and American Psychological Association (APA) PsycINFO. Search was restricted to English language publications. Following the objectives of this study, study design filters within databases were used to restrict the search to SRs and MA, where available. The reference lists of included SRs were also searched for potentially relevant publications.

The search terms included keywords, truncations, and subject headings for the key concepts in the review question: SRs and/or MA, methods, and evaluation. Some of the terms were adopted from the search strategy used in a previous review by Robson et al., which reviewed primary studies on methodological approaches used in study selection, data extraction, and quality appraisal steps of SR process. 14 Individual search strategies were developed for respective databases by combining the search terms using appropriate proximity and Boolean operators, along with the related subject headings in order to identify SRs and/or MA. 16 , 17 A senior librarian was consulted in the design of the search terms and strategy. Appendix A presents the detailed search strategies for all five databases.

2.3. Study selection and data extraction

Title and abstract screening of references were performed in three steps. First, one reviewer (PV) screened all the titles and excluded obviously irrelevant citations, for example, articles on topics not related to SRs, non‐SR publications (such as randomized controlled trials, observational studies, scoping reviews, etc.). Next, from the remaining citations, a random sample of 200 titles and abstracts were screened against the predefined eligibility criteria by two reviewers (PV and MM), independently, in duplicate. Discrepancies were discussed and resolved by consensus. This step ensured that the responses of the two reviewers were calibrated for consistency in the application of the eligibility criteria in the screening process. Finally, all the remaining titles and abstracts were reviewed by a single “calibrated” reviewer (PV) to identify potential full‐text records. Full‐text screening was performed by at least two authors independently (PV screened all the records, and duplicate assessment was conducted by MM, HC, or MG), with discrepancies resolved via discussions or by consulting a third reviewer.

Data related to review characteristics, results, key findings, and conclusions were extracted by at least two reviewers independently (PV performed data extraction for all the reviews and duplicate extraction was performed by AP, HC, or MG).

2.4. Quality assessment of included reviews

The quality assessment of the included SRs was performed using the AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews). The tool consists of a 16‐item checklist addressing critical and noncritical domains. 18 For the purpose of this study, the domain related to MA was reclassified from critical to noncritical, as SRs with and without MA were included. The other six critical domains were used according to the tool guidelines. 18 Two reviewers (PV and AP) independently responded to each of the 16 items in the checklist with either “yes,” “partial yes,” or “no.” Based on the interpretations of the critical and noncritical domains, the overall quality of the review was rated as high, moderate, low, or critically low. 18 Disagreements were resolved through discussion or by consulting a third reviewer.

2.5. Data synthesis

To provide an understandable summary of existing evidence syntheses, characteristics of the methods evaluated in the included SRs were examined and key findings were categorized and presented based on the corresponding step in the SR process. The categories of key elements within each step were discussed and agreed by the authors. Results of the included reviews were tabulated and summarized descriptively, along with a discussion on any overlap in the primary studies. 15 No quantitative analyses of the data were performed.

From 41,556 unique citations identified through literature search, 50 full‐text records were reviewed, and nine systematic reviews 14 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 were deemed eligible for inclusion. The flow of studies through the screening process is presented in Figure  1 . A list of excluded studies with reasons can be found in Appendix B .

Study selection flowchart

3.1. Characteristics of included reviews

Table  1 summarizes the characteristics of included SRs. The majority of the included reviews (six of nine) were published after 2010. 14 , 22 , 23 , 24 , 25 , 26 Four of the nine included SRs were Cochrane reviews. 20 , 21 , 22 , 23 The number of databases searched in the reviews ranged from 2 to 14, 2 reviews searched gray literature sources, 24 , 25 and 7 reviews included a supplementary search strategy to identify relevant literature. 14 , 19 , 20 , 21 , 22 , 23 , 26 Three of the included SRs (all Cochrane reviews) included an integrated MA. 20 , 21 , 23

Characteristics of included studies

SR = systematic review; MA = meta‐analysis; RCT = randomized controlled trial; CCT = controlled clinical trial; N/R = not reported.

The included SRs evaluated 24 unique methodological approaches (26 in total) used across five steps in the SR process; 8 SRs evaluated 6 approaches, 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 while 1 review evaluated 18 approaches. 14 Exclusion of gray or unpublished literature 21 , 26 and blinding of reviewers for RoB assessment 14 , 23 were evaluated in two reviews each. Included SRs evaluated methods used in five different steps in the SR process, including methods used in defining the scope of review ( n  = 3), literature search ( n  = 3), study selection ( n  = 2), data extraction ( n  = 1), and RoB assessment ( n  = 2) (Table  2 ).

Summary of findings from review evaluating systematic review methods

There was some overlap in the primary studies evaluated in the included SRs on the same topics: Schmucker et al. 26 and Hopewell et al. 21 ( n  = 4), Hopewell et al. 20 and Crumley et al. 19 ( n  = 30), and Robson et al. 14 and Morissette et al. 23 ( n  = 4). There were no conflicting results between any of the identified SRs on the same topic.

3.2. Methodological quality of included reviews

Overall, the quality of the included reviews was assessed as moderate at best (Table  2 ). The most common critical weakness in the reviews was failure to provide justification for excluding individual studies (four reviews). Detailed quality assessment is provided in Appendix C .

3.3. Evidence on systematic review methods

3.3.1. methods for defining review scope and eligibility.

Two SRs investigated the effect of excluding data obtained from gray or unpublished sources on the pooled effect estimates of MA. 21 , 26 Hopewell et al. 21 reviewed five studies that compared the impact of gray literature on the results of a cohort of MA of RCTs in health care interventions. Gray literature was defined as information published in “print or electronic sources not controlled by commercial or academic publishers.” Findings showed an overall greater treatment effect for published trials than trials reported in gray literature. In a more recent review, Schmucker et al. 26 addressed similar objectives, by investigating gray and unpublished data in medicine. In addition to gray literature, defined similar to the previous review by Hopewell et al., the authors also evaluated unpublished data—defined as “supplemental unpublished data related to published trials, data obtained from the Food and Drug Administration  or other regulatory websites or postmarketing analyses hidden from the public.” The review found that in majority of the MA, excluding gray literature had little or no effect on the pooled effect estimates. The evidence was limited to conclude if the data from gray and unpublished literature had an impact on the conclusions of MA. 26

Morrison et al. 24 examined five studies measuring the effect of excluding non‐English language RCTs on the summary treatment effects of SR‐based MA in various fields of conventional medicine. Although none of the included studies reported major difference in the treatment effect estimates between English only and non‐English inclusive MA, the review found inconsistent evidence regarding the methodological and reporting quality of English and non‐English trials. 24 As such, there might be a risk of introducing “language bias” when excluding non‐English language RCTs. The authors also noted that the numbers of non‐English trials vary across medical specialties, as does the impact of these trials on MA results. Based on these findings, Morrison et al. 24 conclude that literature searches must include non‐English studies when resources and time are available to minimize the risk of introducing “language bias.”

3.3.2. Methods for searching studies

Crumley et al. 19 analyzed recall (also referred to as “sensitivity” by some researchers; defined as “percentage of relevant studies identified by the search”) and precision (defined as “percentage of studies identified by the search that were relevant”) when searching a single resource to identify randomized controlled trials and controlled clinical trials, as opposed to searching multiple resources. The studies included in their review frequently compared a MEDLINE only search with the search involving a combination of other resources. The review found low median recall estimates (median values between 24% and 92%) and very low median precisions (median values between 0% and 49%) for most of the electronic databases when searched singularly. 19 A between‐database comparison, based on the type of search strategy used, showed better recall and precision for complex and Cochrane Highly Sensitive search strategies (CHSSS). In conclusion, the authors emphasize that literature searches for trials in SRs must include multiple sources. 19

In an SR comparing handsearching and electronic database searching, Hopewell et al. 20 found that handsearching retrieved more relevant RCTs (retrieval rate of 92%−100%) than searching in a single electronic database (retrieval rates of 67% for PsycINFO/PsycLIT, 55% for MEDLINE, and 49% for Embase). The retrieval rates varied depending on the quality of handsearching, type of electronic search strategy used (e.g., simple, complex or CHSSS), and type of trial reports searched (e.g., full reports, conference abstracts, etc.). The authors concluded that handsearching was particularly important in identifying full trials published in nonindexed journals and in languages other than English, as well as those published as abstracts and letters. 20

The effectiveness of checking reference lists to retrieve additional relevant studies for an SR was investigated by Horsley et al. 22 The review reported that checking reference lists yielded 2.5%–40% more studies depending on the quality and comprehensiveness of the electronic search used. The authors conclude that there is some evidence, although from poor quality studies, to support use of checking reference lists to supplement database searching. 22

3.3.3. Methods for selecting studies

Three approaches relevant to reviewer characteristics, including number, experience, and blinding of reviewers involved in the screening process were highlighted in an SR by Robson et al. 14 Based on the retrieved evidence, the authors recommended that two independent, experienced, and unblinded reviewers be involved in study selection. 14 A modified approach has also been suggested by the review authors, where one reviewer screens and the other reviewer verifies the list of excluded studies, when the resources are limited. It should be noted however this suggestion is likely based on the authors’ opinion, as there was no evidence related to this from the studies included in the review.

Robson et al. 14 also reported two methods describing the use of technology for screening studies: use of Google Translate for translating languages (for example, German language articles to English) to facilitate screening was considered a viable method, while using two computer monitors for screening did not increase the screening efficiency in SR. Title‐first screening was found to be more efficient than simultaneous screening of titles and abstracts, although the gain in time with the former method was lesser than the latter. Therefore, considering that the search results are routinely exported as titles and abstracts, Robson et al. 14 recommend screening titles and abstracts simultaneously. However, the authors note that these conclusions were based on very limited number (in most instances one study per method) of low‐quality studies. 14

3.3.4. Methods for data extraction

Robson et al. 14 examined three approaches for data extraction relevant to reviewer characteristics, including number, experience, and blinding of reviewers (similar to the study selection step). Although based on limited evidence from a small number of studies, the authors recommended use of two experienced and unblinded reviewers for data extraction. The experience of the reviewers was suggested to be especially important when extracting continuous outcomes (or quantitative) data. However, when the resources are limited, data extraction by one reviewer and a verification of the outcomes data by a second reviewer was recommended.

As for the methods involving use of technology, Robson et al. 14 identified limited evidence on the use of two monitors to improve the data extraction efficiency and computer‐assisted programs for graphical data extraction. However, use of Google Translate for data extraction in non‐English articles was not considered to be viable. 14 In the same review, Robson et al. 14 identified evidence supporting contacting authors for obtaining additional relevant data.

3.3.5. Methods for RoB assessment

Two SRs examined the impact of blinding of reviewers for RoB assessments. 14 , 23 Morissette et al. 23 investigated the mean differences between the blinded and unblinded RoB assessment scores and found inconsistent differences among the included studies providing no definitive conclusions. Similar conclusions were drawn in a more recent review by Robson et al., 14 which included four studies on reviewer blinding for RoB assessment that completely overlapped with Morissette et al. 23

Use of experienced reviewers and provision of additional guidance for RoB assessment were examined by Robson et al. 14 The review concluded that providing intensive training and guidance on assessing studies reporting insufficient data to the reviewers improves RoB assessments. 14 Obtaining additional data related to quality assessment by contacting study authors was also found to help the RoB assessments, although based on limited evidence. When assessing the qualitative or mixed method reviews, Robson et al. 14 recommends the use of a structured RoB tool as opposed to an unstructured tool. No SRs were identified on data synthesis and CoE assessment and reporting steps.

4. DISCUSSION

4.1. summary of findings.

Nine SRs examining 24 unique methods used across five steps in the SR process were identified in this overview. The collective evidence supports some current traditional and modified SR practices, while challenging other approaches. However, the quality of the included reviews was assessed to be moderate at best and in the majority of the included SRs, evidence related to the evaluated methods was obtained from very limited numbers of primary studies. As such, the interpretations from these SRs should be made cautiously.

The evidence gathered from the included SRs corroborate a few current SR approaches. 5 For example, it is important to search multiple resources for identifying relevant trials (RCTs and/or CCTs). The resources must include a combination of electronic database searching, handsearching, and reference lists of retrieved articles. 5 However, no SRs have been identified that evaluated the impact of the number of electronic databases searched. A recent study by Halladay et al. 27 found that articles on therapeutic intervention, retrieved by searching databases other than PubMed (including Embase), contributed only a small amount of information to the MA and also had a minimal impact on the MA results. The authors concluded that when the resources are limited and when large number of studies are expected to be retrieved for the SR or MA, PubMed‐only search can yield reliable results. 27

Findings from the included SRs also reiterate some methodological modifications currently employed to “expedite” the SR process. 10 , 11 For example, excluding non‐English language trials and gray/unpublished trials from MA have been shown to have minimal or no impact on the results of MA. 24 , 26 However, the efficiency of these SR methods, in terms of time and the resources used, have not been evaluated in the included SRs. 24 , 26 Of the SRs included, only two have focused on the aspect of efficiency 14 , 25 ; O'Mara‐Eves et al. 25 report some evidence to support the use of text‐mining approaches for title and abstract screening in order to increase the rate of screening. Moreover, only one included SR 14 considered primary studies that evaluated reliability (inter‐ or intra‐reviewer consistency) and accuracy (validity when compared against a “gold standard” method) of the SR methods. This can be attributed to the limited number of primary studies that evaluated these outcomes when evaluating the SR methods. 14 Lack of outcome measures related to reliability, accuracy, and efficiency precludes making definitive recommendations on the use of these methods/modifications. Future research studies must focus on these outcomes.

Some evaluated methods may be relevant to multiple steps; for example, exclusions based on publication status (gray/unpublished literature) and language of publication (non‐English language studies) can be outlined in the a priori eligibility criteria or can be incorporated as search limits in the search strategy. SRs included in this overview focused on the effect of study exclusions on pooled treatment effect estimates or MA conclusions. Excluding studies from the search results, after conducting a comprehensive search, based on different eligibility criteria may yield different results when compared to the results obtained when limiting the search itself. 28 Further studies are required to examine this aspect.

Although we acknowledge the lack of standardized quality assessment tools for methodological study designs, we adhered to the Cochrane criteria for identifying SRs in this overview. This was done to ensure consistency in the quality of the included evidence. As a result, we excluded three reviews that did not provide any form of discussion on the quality of the included studies. The methods investigated in these reviews concern supplementary search, 29 data extraction, 12 and screening. 13 However, methods reported in two of these three reviews, by Mathes et al. 12 and Waffenschmidt et al., 13 have also been examined in the SR by Robson et al., 14 which was included in this overview; in most instances (with the exception of one study included in Mathes et al. 12 and Waffenschmidt et al. 13 each), the studies examined in these excluded reviews overlapped with those in the SR by Robson et al. 14

One of the key gaps in the knowledge observed in this overview was the dearth of SRs on the methods used in the data synthesis component of SR. Narrative and quantitative syntheses are the two most commonly used approaches for synthesizing data in evidence synthesis. 5 There are some published studies on the proposed indications and implications of these two approaches. 30 , 31 These studies found that both data synthesis methods produced comparable results and have their own advantages, suggesting that the choice of the method must be based on the purpose of the review. 31 With increasing number of “expedited” SR approaches (so called “rapid reviews”) avoiding MA, 10 , 11 further research studies are warranted in this area to determine the impact of the type of data synthesis on the results of the SR.

4.2. Implications for future research

The findings of this overview highlight several areas of paucity in primary research and evidence synthesis on SR methods. First, no SRs were identified on methods used in two important components of the SR process, including data synthesis and CoE and reporting. As for the included SRs, a limited number of evaluation studies have been identified for several methods. This indicates that further research is required to corroborate many of the methods recommended in current SR guidelines. 4 , 5 , 6 , 7 Second, some SRs evaluated the impact of methods on the results of quantitative synthesis and MA conclusions. Future research studies must also focus on the interpretations of SR results. 28 , 32 Finally, most of the included SRs were conducted on specific topics related to the field of health care, limiting the generalizability of the findings to other areas. It is important that future research studies evaluating evidence syntheses broaden the objectives and include studies on different topics within the field of health care.

4.3. Strengths and limitations

To our knowledge, this is the first overview summarizing current evidence from SRs and MA on different methodological approaches used in several fundamental steps in SR conduct. The overview methodology followed well established guidelines and strict criteria defined for the inclusion of SRs.

There are several limitations related to the nature of the included reviews. Evidence for most of the methods investigated in the included reviews was derived from a limited number of primary studies. Also, the majority of the included SRs may be considered outdated as they were published (or last updated) more than 5 years ago 33 ; only three of the nine SRs have been published in the last 5 years. 14 , 25 , 26 Therefore, important and recent evidence related to these topics may not have been included. Substantial numbers of included SRs were conducted in the field of health, which may limit the generalizability of the findings. Some method evaluations in the included SRs focused on quantitative analyses components and MA conclusions only. As such, the applicability of these findings to SR more broadly is still unclear. 28 Considering the methodological nature of our overview, limiting the inclusion of SRs according to the Cochrane criteria might have resulted in missing some relevant evidence from those reviews without a quality assessment component. 12 , 13 , 29 Although the included SRs performed some form of quality appraisal of the included studies, most of them did not use a standardized RoB tool, which may impact the confidence in their conclusions. Due to the type of outcome measures used for the method evaluations in the primary studies and the included SRs, some of the identified methods have not been validated against a reference standard.

Some limitations in the overview process must be noted. While our literature search was exhaustive covering five bibliographic databases and supplementary search of reference lists, no gray sources or other evidence resources were searched. Also, the search was primarily conducted in health databases, which might have resulted in missing SRs published in other fields. Moreover, only English language SRs were included for feasibility. As the literature search retrieved large number of citations (i.e., 41,556), the title and abstract screening was performed by a single reviewer, calibrated for consistency in the screening process by another reviewer, owing to time and resource limitations. These might have potentially resulted in some errors when retrieving and selecting relevant SRs. The SR methods were grouped based on key elements of each recommended SR step, as agreed by the authors. This categorization pertains to the identified set of methods and should be considered subjective.

5. CONCLUSIONS

This overview identified limited SR‐level evidence on various methodological approaches currently employed during five of the seven fundamental steps in the SR process. Limited evidence was also identified on some methodological modifications currently used to expedite the SR process. Overall, findings highlight the dearth of SRs on SR methodologies, warranting further work to confirm several current recommendations on conventional and expedited SR processes.

CONFLICT OF INTEREST

The authors declare no conflicts of interest.

Supporting information

APPENDIX A: Detailed search strategies

ACKNOWLEDGMENTS

The first author is supported by a La Trobe University Full Fee Research Scholarship and a Graduate Research Scholarship.

Open Access Funding provided by La Trobe University.

Veginadu P, Calache H, Gussy M, Pandian A, Masood M. An overview of methodological approaches in systematic reviews . J Evid Based Med . 2022; 15 :39–54. 10.1111/jebm.12468 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]

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How to write the methods section of a systematic review

Home | Blog | How To | How to write the methods section of a systematic review

Covidence breaks down how to write a methods section

The methods section of your systematic review describes what you did, how you did it, and why. Readers need this information to interpret the results and conclusions of the review. Often, a lot of information needs to be distilled into just a few paragraphs. This can be a challenging task, but good preparation and the right tools will help you to set off in the right direction 🗺️🧭.

Systematic reviews are so-called because they are conducted in a way that is rigorous and replicable. So it’s important that these methods are reported in a way that is thorough, clear, and easy to navigate for the reader – whether that’s a patient, a healthcare worker, or a researcher. 

Like most things in a systematic review, the methods should be planned upfront and ideally described in detail in a project plan or protocol. Reviews of healthcare interventions follow the PRISMA guidelines for the minimum set of items to report in the methods section. But what else should be included? It’s a good idea to consider what readers will want to know about the review methods and whether the journal you’re planning to submit the work to has expectations on the reporting of methods. Finding out in advance will help you to plan what to include.

Describe what happened

While the research plan sets out what you intend to do, the methods section is a write-up of what actually happened. It’s not a simple case of rewriting the plan in the past tense – you will also need to discuss and justify deviations from the plan and describe the handling of issues that were unforeseen at the time the plan was written. For this reason, it is useful to make detailed notes before, during, and after the review is completed. Relying on memory alone risks losing valuable information and trawling through emails when the deadline is looming can be frustrating and time consuming! 

Keep it brief

The methods section should be succinct but include all the noteworthy information. This can be a difficult balance to achieve. A useful strategy is to aim for a brief description that signposts the reader to a separate section or sections of supporting information. This could include datasets, a flowchart to show what happened to the excluded studies, a collection of search strategies, and tables containing detailed information about the studies.This separation keeps the review short and simple while enabling the reader to drill down to the detail as needed. And if the methods follow a well-known or standard process, it might suffice to say so and give a reference, rather than describe the process at length. 

Follow a structure

A clear structure provides focus. Use of descriptive headings keeps the writing on track and helps the reader get to key information quickly. What should the structure of the methods section look like? As always, a lot depends on the type of review but it will certainly contain information relating to the following areas:

• Selection criteria ⭕
• Data collection and analysis 👩‍💻
• Study quality and risk of bias ⚖️

Let’s look at each of these in turn.

1. Selection criteria ⭕

The criteria for including and excluding studies are listed here. This includes detail about the types of studies, the types of participants, the types of interventions and the types of outcomes and how they were measured. 

2. Search 🕵🏾‍♀️

Comprehensive reporting of the search is important because this means it can be evaluated and replicated. The search strategies are included in the review, along with details of the databases searched. It’s also important to list any restrictions on the search (for example, language), describe how resources other than electronic databases were searched (for example,  non-indexed journals), and give the date that the searches were run. The PRISMA-S extension provides guidance on reporting literature searches. 

Systematic reviewer pro-tip:

 Copy and paste the search strategy to avoid introducing typos

3. Data collection and analysis 👩‍💻

This section describes:

• how studies were selected for inclusion in the review
• how study data were extracted from the study reports
• how study data were combined for analysis and synthesis

To describe how studies were selected for inclusion , review teams outline the screening process. Covidence uses reviewers’ decision data to automatically populate a PRISMA flow diagram for this purpose. Covidence can also calculate Cohen’s kappa to enable review teams to report the level of agreement among individual reviewers during screening.

To describe how study data were extracted from the study reports , reviewers outline the form that was used, any pilot-testing that was done, and the items that were extracted from the included studies. An important piece of information to include here is the process used to resolve conflict among the reviewers. Covidence’s data extraction tool saves reviewers’ comments and notes in the system as they work. This keeps the information in one place for easy retrieval ⚡.

To describe how study data were combined for analysis and synthesis, reviewers outline the type of synthesis (narrative or quantitative, for example), the methods for grouping data, the challenges that came up, and how these were dealt with. If the review includes a meta-analysis, it will detail how this was performed and how the treatment effects were measured.

4. Study quality and risk of bias ⚖️

Because the results of systematic reviews can be affected by many types of bias, reviewers make every effort to minimise it and to show the reader that the methods they used were appropriate. This section describes the methods used to assess study quality and an assessment of the risk of bias across a range of domains. 

Steps to assess the risk of bias in studies include looking at how study participants were assigned to treatment groups and whether patients and/or study assessors were blinded to the treatment given. Reviewers also report their assessment of the risk of bias due to missing outcome data, whether that is due to participant drop-out or non-reporting of the outcomes by the study authors.

Covidence’s default template for assessing study quality is Cochrane’s risk of bias tool but it is also possible to start from scratch and build a tool with a set of custom domains if you prefer.

Careful planning, clear writing, and a structured approach are key to a good methods section. A methodologist will be able to refer review teams to examples of good methods reporting in the literature. Covidence helps reviewers to screen references, extract data and complete risk of bias tables quickly and efficiently. Sign up for a free trial today!

Laura Mellor. Portsmouth, UK

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Systematic Review

• Library Help
• What is a Systematic Review (SR)?

Steps of a Systematic Review

• Framing a Research Question
• Developing a Search Strategy
• Searching the Literature
• Managing the Process
• Meta-analysis
• Publishing your Systematic Review

Forms and templates

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• PICO Template
• Inclusion/Exclusion Criteria
• Database Search Log
• Review Matrix
• Cochrane Tool for Assessing Risk of Bias in Included Studies

   • PRISMA Flow Diagram  - Record the numbers of retrieved references and included/excluded studies. You can use the Create Flow Diagram tool to automate the process.

   •  PRISMA Checklist - Checklist of items to include when reporting a systematic review or meta-analysis

PRISMA 2020 and PRISMA-S: Common Questions on Tracking Records and the Flow Diagram

• PROSPERO Template
• Manuscript Template
• Steps of SR (text)
• Steps of SR (visual)
• Steps of SR (PIECES)

Adapted from  A Guide to Conducting Systematic Reviews: Steps in a Systematic Review by Cornell University Library

Source: Cochrane Consumers and Communications  (infographics are free to use and licensed under Creative Commons )

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Doing a Systematic Review: A Student's Guide

Student resources, chapter 1. carrying out a systematic review as a master's thesis.

Explore the wealth of resources available across the web. Here are some good places to start.

Link to the Campbell Collaboration, an organization that prepares, maintains and disseminates systematic reviews in education, crime and justice, social welfare and international development

www.campbellcollaboration.org

Link to the Cochrane Collaboration, an organization that conducts systematic reviews of RCTs of healthcare interventions and diagnostic tests

www.cochrane.org

Systematic Review: Structure and Process

A systematic review is a term that carries specific meaning and refers to a specific process in academic writing. It is the standard for quality and legitimate academic review articles. Academics recognize that, for a study to be reviewed and published, it must follow certain universally-agreed guidelines. Without these guidelines, scientists and publishers would not be able to communicate effectively and meaningfully about a manuscript.

Writers who are new to manuscript writing and academic publishing , such as graduate students, will benefit from careful study of systematic review guidelines and from the advice of experienced authors. The National Center for Biotechnology Information, U.S. National Library of Medicine (a division of the US National Institutes of Health) defines systematic review in this way:

“A systematic review is a protocol driven comprehensive review and synthesis of data focusing on a topic or on related key questions. It is typically performed by experienced methodologists with the input of domain experts.”

There are three types of research:

• Quantitative – results are measured based on numbers and calculations
• Qualitative – results are measured based on observations
• Meta-Analysis – results are based on the review of many related studies

Regardless of their differences, the same protocol is followed for systematic reviews.

Overarching the systematic review is a superstructure or framework. This structure comprises the following components in order: Title-Abstract-Introduction-Methods-Results-Discussion-References. This structure should be familiar to most manuscript writers in an academic or scientific setting, even if they have not yet written a review article.

Full Structure of a Systematic Review

A systematic review follows these steps:

• Designing the question
• Analytic framework
• Evidence mapping
• Critical analysis
• Evidence synthesis

Designing the Question

The design of a research question requires careful selection of language, which mirrors the intent of the research. Research questions are often devised with the use of the PICO structure: Population, Intervention (or Exposure), Control/Comparator, Outcomes. The question will serve as a reference point throughout the research and discussion, so it needs to be explicit.

Analytic Framework

The analytic framework is a visual representation of the PICO structure, drawing connections among all four components. These connections are supported by the evidence provided. It helps the reader quickly understand what is being presented in the review article.

Evidence Mapping

Evidence mapping is a process by which researchers select and reject studies related to the research question at hand. Criteria must be established at the outset for what constitutes a relevant study and what does not. In their article entitled, “ The Global Evidence Mapping Initiative: Scoping research in broad topic areas,” authors Peter Bragge, et al (2011) describe evidence mapping in this way:

“Evidence mapping describes the quantity, design and characteristics of research in broad topic areas…. The breadth of evidence mapping helps to identify evidence gaps, and may guide future research efforts.”

Fundamentally, the critical analysis is used to determine whether or not the study is of high quality. Several criteria are employed to judge the study’s methodology, including topics such as concealment of random allocation, reporting of withdrawals, reporting accuracy, statistical analysis, and assessment of outcomes. Authors and reviewers look for potential bias and misuse of data (or observation) in every area of the study.

Evidence Synthesis

The results of different studies are compared and contrasted, using the research question as a guide. The author provides an evaluation of or answer to the research question based on studies included in the research. The synthesis of a variety of studies has come to be called, “meta-analysis.”

Meta-Analysis

Meta-analysis involves the systematic review of a curated set of studies around a single topic. While a meta-analysis follows a similar protocol to a systematic review , it is research on existing research rather than the creation of new research. Although, one could argue that the synthesis of studies on a single topic does provide a new perspective and new data on that topic or research question.

In their article for the Journal of the Royal Society of Medicine (JRSM), “ Five steps to conducting a systematic review ,” authors Khan, Kunz, Kleijnen, and Antes (2003) describe the five steps necessary to conduct a meta-analysis that qualifies as a systematic review:

Framing the Question

Identifying Relevant Publications

Assessing Study Quality

Summarizing the Evidence

Interpreting the Findings

Essentially, framing the question for a meta-analysis follows the same protocol as designing the question for a systematic review. These authors focus on a variation of PICO: Populations, Interventions or Exposures, Outcomes, and Study Designs. Because a meta-analysis doesn’t necessarily involve a control group or comparator, that element is left out and Study Designs is added on. Reviewers are synthesizing multiple studies and the design of those studies must be considered when framing the question.

The authors must seek and identify relevant published works to inform the meta-analysis. Selected studies/publications must directly correlate to the research question. In addition, authors should record the rationale behind which studies were selected and which were rejected.

This area correlates with “Critical Analysis,” above. While “quality” may seem to be a subjective assessment, there are criteria commonly used in the academic community, which can standardize such an assessment. These include evaluations of the study’s design, the type and amount of research available on a given topic, and the potential for bias in the results. PRISMA is a website that can assist with the search for and assessment of quality studies.

The objective here is to discuss the differences among the studies – characteristics, quality, statistical, etc. – as well as their similarities, particularly in outcomes. For it is not just a comparison of studies that occurs in a meta-analysis; the research question is still the hub of these spokes and the meta-analysis should always point toward the central topic in question.

Bias should be explored when interpreting the findings (favoring one journal or publishing house, favoring a particular author, etc.). The overall quality of the studies should be discussed and “recommendations should be graded by reference to the strengths and weaknesses of the evidence.”

Final Word to Writers

A systematic review is a serious undertaking, usually attempted by a team of writers and researchers, rather than an individual. University libraries are a good place to start when looking for guidance. For example, the University of Toronto has a set of guidelines on their website.

In addition, The Joanna Briggs Institute for Evidence-based Nursing and Midwifery has a PDF entitled, “Appraising Systematic Reviews” and BioMed Central has a good example of a meta-analysis in their “ Methodology in conducting a systematic review of systematic reviews of healthcare interventions” article. Being able to conduct this type of research is an important part of one’s academic career.

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What is different about dissertation research?

Where should i start, what is a literature review, why are literature reviews important, what is a literature search, should i conduct a ‘systematic review’, can i get help with researching my dissertation.

The research process for your dissertation requires a different approach from that you'll have used during your taught modules. Rather than being guided to relevant sources by a lecturer, you’re responsible for finding, selecting, evaluating and managing all your research sources. You'll be using many more sources than you'll have consulted for smaller pieces of assessed work, and perhaps different types of information from those you've used previously, so you need to think carefully about your approach to your information gathering and management activities.

If you're unsure where to start, then some background reading should help you get underway. Start by looking at broad themes and topics of interest, viewing sources like textbooks, subject dictionaries and encyclopaedias which examine larger fundamental concepts, before narrowing your search to look for specific research in your area of study. If you find some really useful material, such as relevant articles or books, you can mine these for all sorts of other useful related sources. For example:

• Has the author written additional material on the topic?
• Does the work have useful keywords or subject terms you can use for further research?
• Does the work have references or a bibliography you can use to explore related material?

A literature review summarises and analyses the literature you've found through your research. In a literature review, the literature itself is the subject of discussion. The aim of a literature review is to demonstrate that you’ve read, and have a good grasp of, the main published material concerning a particular topic or question in your field. A literature review isn’t a straightforward summary of everything you’ve read on a topic. It’s an evaluative analysis of what’s been discovered in your field. The review should describe, summarise, evaluate and clarify this literature. Research and Writing Skills for Dissertations and Projects  is a UCL Moodle course available to all UCL students and looks at the skills associated with researching and writing an extended piece of work. Module 4 focuses on the literature review process.

When academics and industry professionals conduct research, they usually publish the work in books, journal articles and conference proceedings. For the most part, this is the 'literature' you need to find and review. A literature review sets the scene for your work. It places your research in context and shows how it relates to and builds upon the work of others. It’s also your chance to tell people why your work matters, why it’s relevant, and how it contributes original research to your field. Importantly, a literature review helps you find out how to do research. It shows which research methods have worked in the past and which ones haven’t. This can be a big help when planning your own research strategy.

For your dissertation, you’re likely to need to perform a literature search. A literature search is a well-thought-out, organised search and evaluation of literature available on a topic. A well-structured literature search is an effective and efficient way to locate sound evidence on the subject you're researching. 'Literature' can include journal articles, newspaper articles, official publications, conference proceedings, archives, book chapters, etc. View the literature searching page on this guide for further details about planning your search, common search techniques and developing a search strategy.

Systematic reviews are a type of literature review that follow a very rigorous and systematic searching, screening and analysis process. You can find out more about the process on our guide to systematic reviews . Usually a systematic review addresses a focused, structured research question to inform understanding on a particular topic and often to support evidence-based decision-making in that area. To do a full systematic review can be an extremely time-consuming process and requires a lot of resources, but you may want to incorporate some similar methodology, such as systematic approaches to literature searching or data analysis, without necessarily carrying out a full review. This can be considered to be a systematic style review, or a “light” systematic review.

Your Subject Liaison Librarian or Site Library can provide support for your dissertation through their subject guides which offer guidance on accessing quality academic resources. Send them an email for personalised support or book a one-to-one appointment .

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Dissertation Structure & Layout 101: How to structure your dissertation, thesis or research project.

By: Derek Jansen (MBA) Reviewed By: David Phair (PhD) | July 2019

So, you’ve got a decent understanding of what a dissertation is , you’ve chosen your topic and hopefully you’ve received approval for your research proposal . Awesome! Now its time to start the actual dissertation or thesis writing journey.

To craft a high-quality document, the very first thing you need to understand is dissertation structure . In this post, we’ll walk you through the generic dissertation structure and layout, step by step. We’ll start with the big picture, and then zoom into each chapter to briefly discuss the core contents. If you’re just starting out on your research journey, you should start with this post, which covers the big-picture process of how to write a dissertation or thesis .

*The Caveat *

In this post, we’ll be discussing a traditional dissertation/thesis structure and layout, which is generally used for social science research across universities, whether in the US, UK, Europe or Australia. However, some universities may have small variations on this structure (extra chapters, merged chapters, slightly different ordering, etc).

So, always check with your university if they have a prescribed structure or layout that they expect you to work with. If not, it’s safe to assume the structure we’ll discuss here is suitable. And even if they do have a prescribed structure, you’ll still get value from this post as we’ll explain the core contents of each section.  

Overview: S tructuring a dissertation or thesis

• Acknowledgements page
• Abstract (or executive summary)
• Table of contents , list of figures and tables
• Chapter 1: Introduction
• Chapter 2: Literature review
• Chapter 3: Methodology
• Chapter 4: Results
• Chapter 5: Discussion
• Chapter 6: Conclusion
• Reference list

As I mentioned, some universities will have slight variations on this structure. For example, they want an additional “personal reflection chapter”, or they might prefer the results and discussion chapter to be merged into one. Regardless, the overarching flow will always be the same, as this flow reflects the research process , which we discussed here – i.e.:

• The introduction chapter presents the core research question and aims .
• The literature review chapter assesses what the current research says about this question.
• The methodology, results and discussion chapters go about undertaking new research about this question.
• The conclusion chapter (attempts to) answer the core research question .

In other words, the dissertation structure and layout reflect the research process of asking a well-defined question(s), investigating, and then answering the question – see below.

To restate that – the structure and layout of a dissertation reflect the flow of the overall research process . This is essential to understand, as each chapter will make a lot more sense if you “get” this concept. If you’re not familiar with the research process, read this post before going further.

Right. Now that we’ve covered the big picture, let’s dive a little deeper into the details of each section and chapter. Oh and by the way, you can also grab our free dissertation/thesis template here to help speed things up.

The title page of your dissertation is the very first impression the marker will get of your work, so it pays to invest some time thinking about your title. But what makes for a good title? A strong title needs to be 3 things:

• Succinct (not overly lengthy or verbose)
• Specific (not vague or ambiguous)
• Representative of the research you’re undertaking (clearly linked to your research questions)

Typically, a good title includes mention of the following:

• The broader area of the research (i.e. the overarching topic)
• The specific focus of your research (i.e. your specific context)
• Indication of research design (e.g. quantitative , qualitative , or  mixed methods ).

For example:

A quantitative investigation [research design] into the antecedents of organisational trust [broader area] in the UK retail forex trading market [specific context/area of focus].

Again, some universities may have specific requirements regarding the format and structure of the title, so it’s worth double-checking expectations with your institution (if there’s no mention in the brief or study material).

Acknowledgements

This page provides you with an opportunity to say thank you to those who helped you along your research journey. Generally, it’s optional (and won’t count towards your marks), but it is academic best practice to include this.

So, who do you say thanks to? Well, there’s no prescribed requirements, but it’s common to mention the following people:

• Your dissertation supervisor or committee.
• Any professors, lecturers or academics that helped you understand the topic or methodologies.
• Any tutors, mentors or advisors.
• Your family and friends, especially spouse (for adult learners studying part-time).

There’s no need for lengthy rambling. Just state who you’re thankful to and for what (e.g. thank you to my supervisor, John Doe, for his endless patience and attentiveness) – be sincere. In terms of length, you should keep this to a page or less.

Abstract or executive summary

The dissertation abstract (or executive summary for some degrees) serves to provide the first-time reader (and marker or moderator) with a big-picture view of your research project. It should give them an understanding of the key insights and findings from the research, without them needing to read the rest of the report – in other words, it should be able to stand alone .

For it to stand alone, your abstract should cover the following key points (at a minimum):

• Your research questions and aims – what key question(s) did your research aim to answer?
• Your methodology – how did you go about investigating the topic and finding answers to your research question(s)?
• Your findings – following your own research, what did do you discover?
• Your conclusions – based on your findings, what conclusions did you draw? What answers did you find to your research question(s)?

So, in much the same way the dissertation structure mimics the research process, your abstract or executive summary should reflect the research process, from the initial stage of asking the original question to the final stage of answering that question.

In practical terms, it’s a good idea to write this section up last , once all your core chapters are complete. Otherwise, you’ll end up writing and rewriting this section multiple times (just wasting time). For a step by step guide on how to write a strong executive summary, check out this post .

Need a helping hand?

Table of contents

This section is straightforward. You’ll typically present your table of contents (TOC) first, followed by the two lists – figures and tables. I recommend that you use Microsoft Word’s automatic table of contents generator to generate your TOC. If you’re not familiar with this functionality, the video below explains it simply:

If you find that your table of contents is overly lengthy, consider removing one level of depth. Oftentimes, this can be done without detracting from the usefulness of the TOC.

Right, now that the “admin” sections are out of the way, its time to move on to your core chapters. These chapters are the heart of your dissertation and are where you’ll earn the marks. The first chapter is the introduction chapter – as you would expect, this is the time to introduce your research…

It’s important to understand that even though you’ve provided an overview of your research in your abstract, your introduction needs to be written as if the reader has not read that (remember, the abstract is essentially a standalone document). So, your introduction chapter needs to start from the very beginning, and should address the following questions:

• What will you be investigating (in plain-language, big picture-level)?
• Why is that worth investigating? How is it important to academia or business? How is it sufficiently original?
• What are your research aims and research question(s)? Note that the research questions can sometimes be presented at the end of the literature review (next chapter).
• What is the scope of your study? In other words, what will and won’t you cover ?
• How will you approach your research? In other words, what methodology will you adopt?
• How will you structure your dissertation? What are the core chapters and what will you do in each of them?

These are just the bare basic requirements for your intro chapter. Some universities will want additional bells and whistles in the intro chapter, so be sure to carefully read your brief or consult your research supervisor.

If done right, your introduction chapter will set a clear direction for the rest of your dissertation. Specifically, it will make it clear to the reader (and marker) exactly what you’ll be investigating, why that’s important, and how you’ll be going about the investigation. Conversely, if your introduction chapter leaves a first-time reader wondering what exactly you’ll be researching, you’ve still got some work to do.

Now that you’ve set a clear direction with your introduction chapter, the next step is the literature review . In this section, you will analyse the existing research (typically academic journal articles and high-quality industry publications), with a view to understanding the following questions:

• What does the literature currently say about the topic you’re investigating?
• Is the literature lacking or well established? Is it divided or in disagreement?
• How does your research fit into the bigger picture?
• How does your research contribute something original?
• How does the methodology of previous studies help you develop your own?

Depending on the nature of your study, you may also present a conceptual framework towards the end of your literature review, which you will then test in your actual research.

Again, some universities will want you to focus on some of these areas more than others, some will have additional or fewer requirements, and so on. Therefore, as always, its important to review your brief and/or discuss with your supervisor, so that you know exactly what’s expected of your literature review chapter.

Now that you’ve investigated the current state of knowledge in your literature review chapter and are familiar with the existing key theories, models and frameworks, its time to design your own research. Enter the methodology chapter – the most “science-ey” of the chapters…

In this chapter, you need to address two critical questions:

• Exactly HOW will you carry out your research (i.e. what is your intended research design)?
• Exactly WHY have you chosen to do things this way (i.e. how do you justify your design)?

Remember, the dissertation part of your degree is first and foremost about developing and demonstrating research skills . Therefore, the markers want to see that you know which methods to use, can clearly articulate why you’ve chosen then, and know how to deploy them effectively.

Importantly, this chapter requires detail – don’t hold back on the specifics. State exactly what you’ll be doing, with who, when, for how long, etc. Moreover, for every design choice you make, make sure you justify it.

In practice, you will likely end up coming back to this chapter once you’ve undertaken all your data collection and analysis, and revise it based on changes you made during the analysis phase. This is perfectly fine. Its natural for you to add an additional analysis technique, scrap an old one, etc based on where your data lead you. Of course, I’m talking about small changes here – not a fundamental switch from qualitative to quantitative, which will likely send your supervisor in a spin!

You’ve now collected your data and undertaken your analysis, whether qualitative, quantitative or mixed methods. In this chapter, you’ll present the raw results of your analysis . For example, in the case of a quant study, you’ll present the demographic data, descriptive statistics, inferential statistics , etc.

Typically, Chapter 4 is simply a presentation and description of the data, not a discussion of the meaning of the data. In other words, it’s descriptive, rather than analytical – the meaning is discussed in Chapter 5. However, some universities will want you to combine chapters 4 and 5, so that you both present and interpret the meaning of the data at the same time. Check with your institution what their preference is.

Now that you’ve presented the data analysis results, its time to interpret and analyse them. In other words, its time to discuss what they mean, especially in relation to your research question(s).

What you discuss here will depend largely on your chosen methodology. For example, if you’ve gone the quantitative route, you might discuss the relationships between variables . If you’ve gone the qualitative route, you might discuss key themes and the meanings thereof. It all depends on what your research design choices were.

Most importantly, you need to discuss your results in relation to your research questions and aims, as well as the existing literature. What do the results tell you about your research questions? Are they aligned with the existing research or at odds? If so, why might this be? Dig deep into your findings and explain what the findings suggest, in plain English.

The final chapter – you’ve made it! Now that you’ve discussed your interpretation of the results, its time to bring it back to the beginning with the conclusion chapter . In other words, its time to (attempt to) answer your original research question s (from way back in chapter 1). Clearly state what your conclusions are in terms of your research questions. This might feel a bit repetitive, as you would have touched on this in the previous chapter, but its important to bring the discussion full circle and explicitly state your answer(s) to the research question(s).

Next, you’ll typically discuss the implications of your findings . In other words, you’ve answered your research questions – but what does this mean for the real world (or even for academia)? What should now be done differently, given the new insight you’ve generated?

Lastly, you should discuss the limitations of your research, as well as what this means for future research in the area. No study is perfect, especially not a Masters-level. Discuss the shortcomings of your research. Perhaps your methodology was limited, perhaps your sample size was small or not representative, etc, etc. Don’t be afraid to critique your work – the markers want to see that you can identify the limitations of your work. This is a strength, not a weakness. Be brutal!

This marks the end of your core chapters – woohoo! From here on out, it’s pretty smooth sailing.

The reference list is straightforward. It should contain a list of all resources cited in your dissertation, in the required format, e.g. APA , Harvard, etc.

It’s essential that you use reference management software for your dissertation. Do NOT try handle your referencing manually – its far too error prone. On a reference list of multiple pages, you’re going to make mistake. To this end, I suggest considering either Mendeley or Zotero. Both are free and provide a very straightforward interface to ensure that your referencing is 100% on point. I’ve included a simple how-to video for the Mendeley software (my personal favourite) below:

Some universities may ask you to include a bibliography, as opposed to a reference list. These two things are not the same . A bibliography is similar to a reference list, except that it also includes resources which informed your thinking but were not directly cited in your dissertation. So, double-check your brief and make sure you use the right one.

The very last piece of the puzzle is the appendix or set of appendices. This is where you’ll include any supporting data and evidence. Importantly, supporting is the keyword here.

Your appendices should provide additional “nice to know”, depth-adding information, which is not critical to the core analysis. Appendices should not be used as a way to cut down word count (see this post which covers how to reduce word count ). In other words, don’t place content that is critical to the core analysis here, just to save word count. You will not earn marks on any content in the appendices, so don’t try to play the system!

Time to recap…

And there you have it – the traditional dissertation structure and layout, from A-Z. To recap, the core structure for a dissertation or thesis is (typically) as follows:

• Acknowledgments page

Most importantly, the core chapters should reflect the research process (asking, investigating and answering your research question). Moreover, the research question(s) should form the golden thread throughout your dissertation structure. Everything should revolve around the research questions, and as you’ve seen, they should form both the start point (i.e. introduction chapter) and the endpoint (i.e. conclusion chapter).

I hope this post has provided you with clarity about the traditional dissertation/thesis structure and layout. If you have any questions or comments, please leave a comment below, or feel free to get in touch with us. Also, be sure to check out the rest of the  Grad Coach Blog .

Psst... there’s more!

This post was based on one of our popular Research Bootcamps . If you're working on a research project, you'll definitely want to check this out ...

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36 Comments

many thanks i found it very useful

Glad to hear that, Arun. Good luck writing your dissertation.

Such clear practical logical advice. I very much needed to read this to keep me focused in stead of fretting.. Perfect now ready to start my research!

what about scientific fields like computer or engineering thesis what is the difference in the structure? thank you very much

Thanks so much this helped me a lot!

Very helpful and accessible. What I like most is how practical the advice is along with helpful tools/ links.

Thanks Ade!

Thank you so much sir.. It was really helpful..

You’re welcome!

Hi! How many words maximum should contain the abstract?

Thank you so much 😊 Find this at the right moment

You’re most welcome. Good luck with your dissertation.

best ever benefit i got on right time thank you

Many times Clarity and vision of destination of dissertation is what makes the difference between good ,average and great researchers the same way a great automobile driver is fast with clarity of address and Clear weather conditions .

I guess Great researcher = great ideas + knowledge + great and fast data collection and modeling + great writing + high clarity on all these

You have given immense clarity from start to end.

Morning. Where will I write the definitions of what I’m referring to in my report?

Thank you so much Derek, I was almost lost! Thanks a tonnnn! Have a great day!

Thanks ! so concise and valuable

This was very helpful. Clear and concise. I know exactly what to do now.

Thank you for allowing me to go through briefly. I hope to find time to continue.

Really useful to me. Thanks a thousand times

Very interesting! It will definitely set me and many more for success. highly recommended.

Thank you soo much sir, for the opportunity to express my skills

Usefull, thanks a lot. Really clear

Very nice and easy to understand. Thank you .

That was incredibly useful. Thanks Grad Coach Crew!

My stress level just dropped at least 15 points after watching this. Just starting my thesis for my grad program and I feel a lot more capable now! Thanks for such a clear and helpful video, Emma and the GradCoach team!

Do we need to mention the number of words the dissertation contains in the main document?

It depends on your university’s requirements, so it would be best to check with them 🙂

Such a helpful post to help me get started with structuring my masters dissertation, thank you!

Great video; I appreciate that helpful information

It is so necessary or avital course

This blog is very informative for my research. Thank you

Doctoral students are required to fill out the National Research Council’s Survey of Earned Doctorates

wow this is an amazing gain in my life

This is so good

How can i arrange my specific objectives in my dissertation?

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