The University of Manitoba campuses are located on original lands of Anishinaabeg, Cree, Ojibwe-Cree, Dakota, and Dene peoples, and on the National Homeland of the Red River Métis. More
There is a range of knowledge synthesis types and the type you choose will depend on your research question.
A study of studies. These reviews aim to collect all existing evidence to address a specific research question. The criteria used to select included evidence is pre-defined and responds precisely to the research question. Explicit methods to minimize bias and increase transparency are used to produce reliable synthesis of information. The purpose of this synthesized information is to create strong evidence to inform clinical decision-making, policy and research.
Also known as mapping reviews, scoping reviews are exploratory research projects that systematically map the literature on a topic by identifying key concepts, theories and sources of evidence that inform practice in the field. The main objectives of scoping reviews are to identify gaps in the current research and highlight areas that require further inquiry. They aim to assess the potential size and scope of available research literature (often including ongoing research) and the current level of synthesis available.
An evidence gap map uses deductive research questions to map high level data extraction with predefined coding categories. Generally evidence gap maps answer broad questions, typically using more than eighty studies. There is often use of visual displays for findings, such as a graphical presentation in a matrix table. For examples of evidence gap maps, please see 3ie (International Initiative for Impact Evaluation).
A (condensed) study of studies. Rapid reviews are conducted using the same methods as in a systematic review. Rapid reviews differ from other review types because decisions about the process of conducting the review are centred on the time allotted for the completion of the review. For example, the completeness of the initial search is determined by time constraints and/or the formal quality assessment is time-limited.
A broad account of what has been published on a topic. They are written primarily by researchers working in the topic's area of study. A literature review illustrates what knowledge and ideas have been established on a particular topic, what the strengths and weaknesses are, and to identify controversies in the literature. Literature reviews also formulate questions for further research and inquiry. These types of reviews do not have standardized methodology or reporting guidelines.
Meta-analysis, commonly part of a systematic review, is a statistical technique for combining the findings from disparate quantitative studies. Meta-analysis uses statistical methods to objectively evaluate, synthesize, and summarize results. This type of review may be conducted independently or as part of a systematic review.
A state-of-the-art review summarizes three aspects of a specific area of knowledge:1
State-of-the-art reviews offer insight into the modern conceptualization of a specific phenomenon.2 State-of-the-art reviews provide a broad historical overview and provide insight into possible directions for the future. These reviews allow for subjectivity, as the author(s) decide on significant historical shifts. There is no requirement for all included studies and literature to use the same methodologies (compared to a systematic review and meta-analysis); since there can be different ways of understanding the area of knowledge or phenomenon, summarizing the included literature's data and findings from different study methodologies is possible.
An umbrella review is a review of reviews. It compiles all the evidence from existing reviews on a topic to give a high level overview. An umbrella review is commonly conducted when there are multiple competing interventions for a condition. An overview of reviews about each of these interventions can be useful in determining how to best translate the evidence into practice. Like many other reviews, the aim of an umbrella study is to determine what is known on a topic, what remains unknown, and recommendations are made for what requires further research.
A critical review describes an author’s hypothesis or conceptual model based on key literature in their field of study. One of the aims of the critical review is to demonstrate that the reviewer has a commanding understanding of the literature to the point where they can extrapolate hypotheses on the topic of review. This type of review goes beyond the level of detailed description of the existing literature. While conducting a critical review, the reviewer identifies the most significant research in the field and evaluates the literature based on its contribution to the field (as opposed to a formal quality assessment). This review type is usually narrative or conceptual.
It can be challenging to decide which review is right for your research question. To help you decide, you can use the Which Review is Right for You? tool to decide.
You can also consult Cornell University Library's Review Methodology Decision Tree.
For more information on types of reviews, you can consult:
Doing a Systematic Review by
Written in a friendly, accessible style by an expert team of authors with years of experience in both conducting and supervising systematic reviews, this is the perfect guide to using systematic review methodology in a research project. It provides clear answers to all review-related questions, including: How do I formulate an appropriate review question? What's the best way to manage my review? How do I develop my search strategy? How do I get started with data extraction? How do I assess the quality of a study? How can I analyse and synthesize my data? How should I write up the discussion and conclusion sections of my dissertation or thesis?
Piecing together systematic reviews and other evidence syntheses by 
An Introduction to Systematic Reviews by
Focused on actively using systematic review as method, this book provides clear, step-by-step advice on the logic and processes of systematic reviewing. Stressing the importance of precision and accuracy, this new edition carefully balances a need for insightful theory with real-world pragmatism; it introduces a wide range of cutting-edge approaches to research synthesis including text mining, living reviews and new ideas in mixed methods reviews such as qualitative comparative analysis. The book also includes: A new chapter on statistical synthesis Coverage of computer-assisted methods and relevant software Expanded sections on data extraction and management A guide to working with many different types of data including longitudinal and panel. Packed with examples from across the social sciences, this book helps students and researchers alike in turning systematic reviews into recommendations for policy and practice.
Cochrane Handbook for Systematic Reviews of Interventions by
The revised edition of the Handbook offers the only guide on how to conduct, report and maintain a Cochrane Review 
 The second edition of The Cochrane Handbook for Systematic Reviews of Interventions contains essential guidance for preparing and maintaining Cochrane Reviews of the effects of health interventions. Designed to be an accessible resource, the Handbook will also be of interest to anyone undertaking systematic reviews of interventions outside Cochrane, and many of the principles and methods presented are appropriate for systematic reviews addressing research questions other than effects of interventions. This fully updated edition contains extensive new material on systematic review methods addressing a wide-range of topics including network meta-analysis, equity, complex interventions, narrative synthesis, and automation. Also new to this edition, integrated throughout the Handbook, is the set of standards Cochrane expects its reviews to meet. Written for review authors, editors, trainers and others with an interest in Cochrane Reviews, the second edition of The Cochrane Handbook for Systematic Reviews of Interventions continues to offer an invaluable resource for understanding the role of systematic reviews, critically appraising health research studies and conducting reviews.
Systematic Approaches to a Successful Literature Review by
Whether you are new to literature reviews or working with new types of data, this book takes the guesswork out of writing your literature review. From deciding how much literature to include to managing your data, assessing your sources, and writing results, it outlines a step-by-step process that works with any data. To help you choose best approach for your research, this book includes: · Worksheets and decision aids to help you plan and organise your literature review · Worked examples and case studies to show you what - and what not - to do in practice · Troubleshooting tips and answers to all your frequently asked questions · Online access to a literature review starter template, an exercise workbook, project diary template, and a source credibility checklist. The perfect project support for any social sciences student, this edition also includes a new chapter on analysing mixed methods research.
Making Literature Reviews Work by
This textbook guides the reader on how to undertake high-quality literature reviews, from traditional narrative to protocol-driven reviews. The guidance covers a broad range of purposes, disciplines and research paradigms. Whether the literature review is part of a research project, doctoral study, dissertation or a stand-alone study, the book offers approaches, methods, tools, tips and guidelines to produce more effective literature reviews in an efficient manner. The numerous examples are drawn from an array of subject areas, such as economics, healthcare, education, medicine, psychology, software engineering amongst others. This makes it worthwhile for a wide range of studies and for reviews into evidence-based interventions, policies, practices and treatments. There is attention given to presenting, reporting and publishing literature reviews. With the additional clarity brought about by explanatory tables and graphs, this textbook is a 'must-have' for all students,researchers, academics and practitioners at any stage of their project or career when engaging with literature. In addition, citizens, policymakers and practitioners will benefit from the guidance with better insight into how literature reviews could and should have been conducted.
Research Synthesis and Meta-Analysis by
The Fifth Edition of Harris Cooper's bestselling text offers practical advice on how to conduct a synthesis of research in the social, behavioral, and health sciences. The book is written in plain language with four running examples drawn from psychology, education, and health science. With ample coverage of literature searching and the technical aspects of meta-analysis, this one-of-a-kind book applies the basic principles of sound data gathering to the task of producing a comprehensive assessment of existing research.
Introduction to Meta-Analysis by
This book provides a clear and thorough introduction to meta-analysis, the process of synthesizing data from a series of separate studies. Meta-analysis has become a critically important tool in fields as diverse as medicine, pharmacology, epidemiology, education, psychology, business, and ecology. Introduction to Meta-Analysis: Outlines the role of meta-analysis in the research process Shows how to compute effects sizes and treatment effects Explains the fixed-effect and random-effects models for synthesizing data Demonstrates how to assess and interpret variation in effect size across studies Clarifies concepts using text and figures, followed by formulas and examples Explains how to avoid common mistakes in meta-analysis Discusses controversies in meta-analysis Features a web site with additional material and exercises A superb combination of lucid prose and informative graphics, written by four of the world's leading experts on all aspects of meta-analysis. Borenstein, Hedges, Higgins, and Rothstein provide a refreshing departure from cookbook approaches with their clear explanations of the what and why of meta-analysis. The book is ideal as a course textbook or for self-study. My students, who used pre-publication versions of some of the chapters, raved about the clarity of the explanations and examples. David Rindskopf, Distinguished Professor of Educational Psychology, City University of New York, Graduate School and University Center, & Editor of the Journal of Educational and Behavioral Statistics. The approach taken by Introduction to Meta-analysis is intended to be primarily conceptual, and it is amazingly successful at achieving that goal. The reader can comfortably skip the formulas and still understand their application and underlying motivation. For the more statistically sophisticated reader, the relevant formulas and worked examples provide a superb practical guide to performing a meta-analysis. The book provides an eclectic mix of examples from education, social science, biomedical studies, and even ecology. For anyone considering leading a course in meta-analysis, or pursuing self-directed study, Introduction to Meta-analysis would be a clear first choice. Jesse A. Berlin, ScD Introduction to Meta-Analysis is an excellent resource for novices and experts alike. The book provides a clear and comprehensive presentation of all basic and most advanced approaches to meta-analysis. This book will be referenced for decades. Michael A. McDaniel, Professor of Human Resources and Organizational Behavior, Virginia Commonwealth University
Methods of Meta-Analysis by
Designed to provide researchers clear and informative insight into techniques of meta-analysis, the Third Edition of Methods of Meta-Analysis: Correcting Error and Bias in Research Findings is the most comprehensive text on meta-analysis available today. It is the only book that presents a full and usable treatment of the role of study artifacts in distorting study results, as well as methods for correcting results for such biases and errors. Meta-analysis is arguably the most important methodological innovation in the last thirty-five years, due to its immense impact on the development of cumulative knowledge and professional practice. This text, now in its updated Third Edition, has been revised to cover the newest developments in meta-analysis methods, evaluation, correction, and more. This reader-friendly book is the definitive resource on meta-analysis.
A Guide to Qualitative Meta-Synthesis by
A Guide to Qualitative Meta-synthesis provides accessible guidelines for conducting all phases of theory-generating meta-synthesis research, including data collection, analysis, and theory generation. It is a research methodology that is designed to generate evidence-based theory by extracting, analyzing, and synthesizing qualitative findings from across published investigations. These theories provide scaffolding that can be used by health-care providers and other professionals to make context-based decisions and implement situation-specific actions. Theory-generating meta-synthesis methods stem from the qualitative research paradigm, especially grounded theory. Systematic and rigorous methods are used to identify topically related research reports that provide qualitative findings for analysis. The subsequent analysis of the data goes beyond merely reorganizing and recategorizing research findings. Newly synthesized concepts are developed, and the dynamic relationships among them are fully articulated. The validity of the resultant theory is ensured based on theoretical, methodological, and researcher triangulation; unbiased data collection and sampling strategies; inductive-deductive data analysis and synthesis strategies; and continuous reflexivity. Meta-synthesis-generated theories are highly important in environments where the use of normalized algorithms, guidelines, and protocols are on the rise. The types of theories discussed in this book will help service providers customize standardized tools so that the most effective evidence-based, yet individualized, interventions can be implemented.
Content on this page is reused from the Neil John Maclean Health Sciences Library's guide, Cornell University Library's Guide to Evidence Synthesis, Grant & Booth (2009), and Barry, Merkebu, & Varpio (2022a, 2022b).