- Locations and Hours
- UCLA Library
- Research Guides
- Biomedical Library Guides

Systematic Reviews
Systematic reviews and the ucla library, what is a systematic review, is your review systematic, why do a systematic review.
- Our Service
- Types of Literature Reviews
- Planning Your Systematic Review
- Database Searching
- Creating the Search
- Search Filters & Hedges
- Grey Literature
- Managing & Appraising Results
- Further Resources
Working on a systematic review? Librarians at the UCLA Biomedical Library can help you! The UCLA Biomedical Library offers a systematic review service to research staff, graduate students and faculty in all departments. To initiate a consultation about your systematic review click through to our online scheduling calendar .
At this time, due to limited staffing, our consultation services only include:
- Choosing the best review methodology to fit your timeline, question, and discipline
- Selecting search terms, databases, and expert search strategies
- Organizing search results using citation management (EndNote)
A systematic review is fundamentally different from a traditional narrative review. For more information, see Types of Literature Reviews .
A systematic review is defined as: "A scientific investigation that focuses on a specific question and that uses explicit, planned scientific methods to identify, select, assess, and summarize the findings of similar but separate studies. It may or may not include a quantitative synthesis of the results from separate studies (meta-analysis) depending on the available data." IOM p 1 .
According to the Cochrane Handbook , section 1.2.2, "the key characteristics of a systematic review are:
- a clearly stated set of objectives with pre-defined eligibility criteria for studies;
- an explicit, reproducible methodology ;
- a systematic search that attempts to identify all studies that would meet the eligibility criteria;
- an assessment of the validity of the findings of the included studies, for example through the assessment of risk of bias; and
- a systematic presentation , and synthesis, of the characteristics and findings of the included studies."
Green S, Higgins JPT, Alderson P, Clarke M, Mulrow CD, Oxman AD. Chapter 1: Introduction. In: Higgins JPT, Green S (editors), Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011). The Cochrane Collaboration , 2011. Available from www.cochrane-handbook.org .
Are you sure your review is systematic ? A systematic review requires…
- More than one screener
- An extensive search strategy utilizing both controlled vocabulary terms and keywords
- Searching more than one database
- For more information, read the Institute of Medicine's Standards for Systematic Reviews
You can also use this primer geared towards beginners for a better understanding of the differences between types of reviews and the overall steps of a systematic review:
- Craig A. Umscheid; A Primer on Performing Systematic Reviews and Meta-analyses, Clinical Infectious Diseases, Volume 57, Issue 5, 1 September 2013, Pages 725–734, https://doi.org/10.1093/cid/cit333
The goal of a systematic review is to reduce bias and produce high quality evidence.
Rigorous systematic reviews are at the top of representations of research evidence (see below). The synthesis of multiple high-quality studies creates a single product out of all the best known evidence.
(from the University of Pittsburgh)
- Next: Our Service >>
- Last Updated: Oct 26, 2022 10:51 AM
- URL: https://guides.library.ucla.edu/systematicreviews

Literature Review: Types of literature reviews
- Traditional or narrative literature reviews
- Scoping Reviews
- Systematic literature reviews
- Annotated bibliography
- Keeping up to date with literature
- Finding a thesis
- Evaluating sources and critical appraisal of literature
- Managing and analysing your literature
- Further reading and resources
Types of literature reviews

The type of literature review you write will depend on your discipline and whether you are a researcher writing your PhD, publishing a study in a journal or completing an assessment task in your undergraduate study.
A literature review for a subject in an undergraduate degree will not be as comprehensive as the literature review required for a PhD thesis.
An undergraduate literature review may be in the form of an annotated bibliography or a narrative review of a small selection of literature, for example ten relevant articles. If you are asked to write a literature review, and you are an undergraduate student, be guided by your subject coordinator or lecturer.
The common types of literature reviews will be explained in the pages of this section.
- Narrative or traditional literature reviews
- Critically Appraised Topic (CAT)
- Scoping reviews
- Annotated bibliographies
These are not the only types of reviews of literature that can be conducted. Often the term "review" and "literature" can be confusing and used in the wrong context. Grant and Booth (2009) attempt to clear up this confusion by discussing 14 review types and the associated methodology, and advantages and disadvantages associated with each review.
Grant, M. J. and Booth, A. (2009), A typology of reviews: an analysis of 14 review types and associated methodologies . Health Information & Libraries Journal, 26 , 91–108. doi:10.1111/j.1471-1842.2009.00848.x
What's the difference between reviews?
Researchers, academics, and librarians all use various terms to describe different types of literature reviews, and there is often inconsistency in the ways the types are discussed. Here are a couple of simple explanations.
- The image below describes common review types in terms of speed, detail, risk of bias, and comprehensiveness:

"Schematic of the main differences between the types of literature review" by Brennan, M. L., Arlt, S. P., Belshaw, Z., Buckley, L., Corah, L., Doit, H., Fajt, V. R., Grindlay, D., Moberly, H. K., Morrow, L. D., Stavisky, J., & White, C. (2020). Critically Appraised Topics (CATs) in veterinary medicine: Applying evidence in clinical practice. Frontiers in Veterinary Science, 7 , 314. https://doi.org/10.3389/fvets.2020.00314 is licensed under CC BY 3.0
- The table below lists four of the most common types of review , as adapted from a widely used typology of fourteen types of reviews (Grant & Booth, 2009).
Grant, M.J. & Booth, A. (2009). A typology of reviews: An analysis of 14 review types and associated methodologies. Health Information & Libraries Journal, 26 (2), 91-108. https://doi.org/10.1111/j.1471-1842.2009.00848.x
See also the Library's Literature Review guide.
Critical Appraised Topic (CAT)
For information on conducting a Critically Appraised Topic or CAT
Callander, J., Anstey, A. V., Ingram, J. R., Limpens, J., Flohr, C., & Spuls, P. I. (2017). How to write a Critically Appraised Topic: evidence to underpin routine clinical practice. British Journal of Dermatology (1951), 177(4), 1007-1013. https://doi.org/10.1111/bjd.15873
Books on Literature Reviews
- << Previous: Home
- Next: Traditional or narrative literature reviews >>
- Last Updated: Jan 24, 2023 11:45 AM
- URL: https://libguides.csu.edu.au/review

Charles Sturt University is an Australian University, TEQSA Provider Identification: PRV12018. CRICOS Provider: 00005F.
Have a language expert improve your writing
Run a free plagiarism check in 10 minutes, generate accurate citations for free.
- Knowledge Base
- Methodology
- How to Write a Literature Review | Guide, Examples, & Templates
How to Write a Literature Review | Guide, Examples, & Templates
Published on January 2, 2023 by Shona McCombes .
What is a literature review? A literature review is a survey of scholarly sources on a specific topic. It provides an overview of current knowledge, allowing you to identify relevant theories, methods, and gaps in the existing research that you can later apply to your paper, thesis, or dissertation topic .
There are five key steps to writing a literature review:
- Search for relevant literature
- Evaluate sources
- Identify themes, debates, and gaps
- Outline the structure
- Write your literature review
A good literature review doesn’t just summarize sources—it analyzes, synthesizes , and critically evaluates to give a clear picture of the state of knowledge on the subject.
Table of contents
What is the purpose of a literature review, examples of literature reviews, step 1 – search for relevant literature, step 2 – evaluate and select sources, step 3 – identify themes, debates, and gaps, step 4 – outline your literature review’s structure, step 5 – write your literature review, free lecture slides, frequently asked questions, introduction.
- Quick Run-through
- Step 1 & 2
When you write a thesis , dissertation , or research paper , you will likely have to conduct a literature review to situate your research within existing knowledge. The literature review gives you a chance to:
- Demonstrate your familiarity with the topic and its scholarly context
- Develop a theoretical framework and methodology for your research
- Position your work in relation to other researchers and theorists
- Show how your research addresses a gap or contributes to a debate
- Evaluate the current state of research and demonstrate your knowledge of the scholarly debates around your topic.
Writing literature reviews is a particularly important skill if you want to apply for graduate school or pursue a career in research. We’ve written a step-by-step guide that you can follow below.

Writing literature reviews can be quite challenging! A good starting point could be to look at some examples, depending on what kind of literature review you’d like to write.
- Example literature review #1: “Why Do People Migrate? A Review of the Theoretical Literature” ( Theoretical literature review about the development of economic migration theory from the 1950s to today.)
- Example literature review #2: “Literature review as a research methodology: An overview and guidelines” ( Methodological literature review about interdisciplinary knowledge acquisition and production.)
- Example literature review #3: “The Use of Technology in English Language Learning: A Literature Review” ( Thematic literature review about the effects of technology on language acquisition.)
- Example literature review #4: “Learners’ Listening Comprehension Difficulties in English Language Learning: A Literature Review” ( Chronological literature review about how the concept of listening skills has changed over time.)
You can also check out our templates with literature review examples and sample outlines at the links below.
Download Word doc Download Google doc
Prevent plagiarism. Run a free check.
Before you begin searching for literature, you need a clearly defined topic .
If you are writing the literature review section of a dissertation or research paper, you will search for literature related to your research problem and questions .
Make a list of keywords
Start by creating a list of keywords related to your research question. Include each of the key concepts or variables you’re interested in, and list any synonyms and related terms. You can add to this list as you discover new keywords in the process of your literature search.
- Social media, Facebook, Instagram, Twitter, Snapchat, TikTok
- Body image, self-perception, self-esteem, mental health
- Generation Z, teenagers, adolescents, youth

Search for relevant sources
Use your keywords to begin searching for sources. Some useful databases to search for journals and articles include:
- Your university’s library catalogue
- Google Scholar
- Project Muse (humanities and social sciences)
- Medline (life sciences and biomedicine)
- EconLit (economics)
- Inspec (physics, engineering and computer science)
You can also use boolean operators to help narrow down your search.
Make sure to read the abstract to find out whether an article is relevant to your question. When you find a useful book or article, you can check the bibliography to find other relevant sources.
You likely won’t be able to read absolutely everything that has been written on your topic, so it will be necessary to evaluate which sources are most relevant to your research question.
For each publication, ask yourself:
- What question or problem is the author addressing?
- What are the key concepts and how are they defined?
- What are the key theories, models, and methods?
- Does the research use established frameworks or take an innovative approach?
- What are the results and conclusions of the study?
- How does the publication relate to other literature in the field? Does it confirm, add to, or challenge established knowledge?
- What are the strengths and weaknesses of the research?
Make sure the sources you use are credible , and make sure you read any landmark studies and major theories in your field of research.
You can use our template to summarize and evaluate sources you’re thinking about using. Click on either button below to download.
Take notes and cite your sources
As you read, you should also begin the writing process. Take notes that you can later incorporate into the text of your literature review.
It is important to keep track of your sources with citations to avoid plagiarism . It can be helpful to make an annotated bibliography , where you compile full citation information and write a paragraph of summary and analysis for each source. This helps you remember what you read and saves time later in the process.
To begin organizing your literature review’s argument and structure, be sure you understand the connections and relationships between the sources you’ve read. Based on your reading and notes, you can look for:
- Trends and patterns (in theory, method or results): do certain approaches become more or less popular over time?
- Themes: what questions or concepts recur across the literature?
- Debates, conflicts and contradictions: where do sources disagree?
- Pivotal publications: are there any influential theories or studies that changed the direction of the field?
- Gaps: what is missing from the literature? Are there weaknesses that need to be addressed?
This step will help you work out the structure of your literature review and (if applicable) show how your own research will contribute to existing knowledge.
- Most research has focused on young women.
- There is an increasing interest in the visual aspects of social media.
- But there is still a lack of robust research on highly visual platforms like Instagram and Snapchat—this is a gap that you could address in your own research.
There are various approaches to organizing the body of a literature review. Depending on the length of your literature review, you can combine several of these strategies (for example, your overall structure might be thematic, but each theme is discussed chronologically).
Chronological
The simplest approach is to trace the development of the topic over time. However, if you choose this strategy, be careful to avoid simply listing and summarizing sources in order.
Try to analyze patterns, turning points and key debates that have shaped the direction of the field. Give your interpretation of how and why certain developments occurred.
If you have found some recurring central themes, you can organize your literature review into subsections that address different aspects of the topic.
For example, if you are reviewing literature about inequalities in migrant health outcomes, key themes might include healthcare policy, language barriers, cultural attitudes, legal status, and economic access.
Methodological
If you draw your sources from different disciplines or fields that use a variety of research methods , you might want to compare the results and conclusions that emerge from different approaches. For example:
- Look at what results have emerged in qualitative versus quantitative research
- Discuss how the topic has been approached by empirical versus theoretical scholarship
- Divide the literature into sociological, historical, and cultural sources
Theoretical
A literature review is often the foundation for a theoretical framework . You can use it to discuss various theories, models, and definitions of key concepts.
You might argue for the relevance of a specific theoretical approach, or combine various theoretical concepts to create a framework for your research.
Like any other academic text , your literature review should have an introduction , a main body, and a conclusion . What you include in each depends on the objective of your literature review.
The introduction should clearly establish the focus and purpose of the literature review.
Depending on the length of your literature review, you might want to divide the body into subsections. You can use a subheading for each theme, time period, or methodological approach.
As you write, you can follow these tips:
- Summarize and synthesize: give an overview of the main points of each source and combine them into a coherent whole
- Analyze and interpret: don’t just paraphrase other researchers — add your own interpretations where possible, discussing the significance of findings in relation to the literature as a whole
- Critically evaluate: mention the strengths and weaknesses of your sources
- Write in well-structured paragraphs: use transition words and topic sentences to draw connections, comparisons and contrasts
In the conclusion, you should summarize the key findings you have taken from the literature and emphasize their significance.
When you’ve finished writing and revising your literature review, don’t forget to proofread thoroughly before submitting. Not a language expert? Check out Scribbr’s professional proofreading services !
This article has been adapted into lecture slides that you can use to teach your students about writing a literature review.
Scribbr slides are free to use, customize, and distribute for educational purposes.
Open Google Slides Download PowerPoint
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 thesis, dissertation , or research paper , in order to situate your work in relation to existing knowledge.
There are several reasons to conduct a literature review at the beginning of a research project:
- To familiarize 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.
The literature review usually comes near the beginning of your thesis or dissertation . After the introduction , it grounds your research in a scholarly field and leads directly to your theoretical framework or methodology .
A literature review is a survey of credible sources on a topic, often used in dissertations , theses, and research papers . Literature reviews give an overview of knowledge on a subject, helping you identify relevant theories and methods, as well as gaps in existing research. Literature reviews are set up similarly to other academic texts , with an introduction , a main body, and a conclusion .
An annotated bibliography is a list of source references that has a short description (called an annotation ) for each of the sources. It is often assigned as part of the research process for a paper .
Cite this Scribbr article
If you want to cite this source, you can copy and paste the citation or click the “Cite this Scribbr article” button to automatically add the citation to our free Citation Generator.
McCombes, S. (2023, January 02). How to Write a Literature Review | Guide, Examples, & Templates. Scribbr. Retrieved February 27, 2023, from https://www.scribbr.com/dissertation/literature-review/
Is this article helpful?
Shona McCombes
Other students also liked, what is a theoretical framework | guide to organizing, what is a research methodology | steps & tips, how to write a research proposal | examples & templates, what is your plagiarism score.

Literature Review Research
Literature review, what is not a literature review, purpose of the literature review, types of literature review.
- Systematic Review
- Literature vs Systematic Review
- Systematic vs Meta-Analysis
- Planning your Literature Review
- Finding information
- Helpful Tips
- Research Tips
- Other Resources
- Citing your Sources
Chat with us!

Education Librarian

- What is a Literature Review?
- Summarizes and analyzes previous research relevant to a topic
- Includes scholarly books and articles published in academic journals
- Can be an specific scholarly paper or a section in a research paper
- Help gather ideas or information
- Keep up to date in current trends and findings
- Help develop new questions
A literature review is important because it:
- Explains the background of research on a topic.
- Demonstrates why a topic is significant to a subject area.
- Helps focus your own research questions or problems
- Discovers relationships between research studies/ideas.
- Suggests unexplored ideas or populations
- Identifies major themes, concepts, and researchers on a topic.
- Tests assumptions; may help counter preconceived ideas and remove unconscious bias.
- Identifies critical gaps, points of disagreement, or potentially flawed methodology or theoretical approaches.
- Indicates potential directions for future research.
Keep in mind the following, a literature review is NOT:
Not an essay
Not an annotated bibliography in which you summarize each article you reviewed. A literature review goes beyond basic summarizing to critically analyze the reviewed works and their relationship to your research question.
Not a research paper where you select resources to support one side of an issue versus another. A lit review should explain and consider all sides of an argument to avoid bias, and areas of agreement and disagreement should be highlighted.
A literature review serves several purposes. For example, it
- provides thorough knowledge of previous studies; introduces seminal works.
- helps focus one’s own research topic.
- identifies a conceptual framework for one’s own research questions or problems; indicates potential directions for future research.
- suggests previously unused or underused methodologies, designs, and quantitative and qualitative strategies.
- identifies gaps in previous studies; identifies flawed methodologies and/or theoretical approaches; avoids replication of mistakes.
- helps the researcher avoid the repetition of earlier research.
- suggests unexplored populations.
- determines whether past studies agree or disagree; identifies controversy in the literature.
- tests assumptions may help counter preconceived ideas and remove unconscious bias.
As Kennedy (2007) notes*, it is important to think of knowledge in a given field as consisting of three layers. First, there are the primary studies that researchers conduct and publish. Second are the reviews of those studies that summarize and offer new interpretations built from and often extending beyond the original studies. Third, there are the perceptions, conclusions, opinion, and interpretations that are shared informally that become part of the lore of field. In composing a literature review, it is important to note that it is often this third layer of knowledge that is cited as "true" even though it often has only a loose relationship to the primary studies and secondary literature reviews.
Given this, while literature reviews are designed to provide an overview and synthesis of pertinent sources you have explored, there are several approaches to how they can be done, depending upon the type of analysis underpinning your study. Listed below are definitions of types of literature reviews:
Argumentative Review This form examines literature selectively in order to support or refute an argument, deeply imbedded assumption, or philosophical problem already established in the literature. The purpose is to develop a body of literature that establishes a contrarian viewpoint. Given the value-laden nature of some social science research [e.g., educational reform; immigration control], argumentative approaches to analyzing the literature can be a legitimate and important form of discourse. However, note that they can also introduce problems of bias when they are used to to make summary claims of the sort found in systematic reviews.
Integrative Review Considered a form of research that reviews, critiques, and synthesizes representative literature on a topic in an integrated way such that new frameworks and perspectives on the topic are generated. The body of literature includes all studies that address related or identical hypotheses. A well-done integrative review meets the same standards as primary research in regard to clarity, rigor, and replication.
Historical Review Few things rest in isolation from historical precedent. Historical reviews are focused on examining research throughout a period of time, often starting with the first time an issue, concept, theory, phenomena emerged in the literature, then tracing its evolution within the scholarship of a discipline. The purpose is to place research in a historical context to show familiarity with state-of-the-art developments and to identify the likely directions for future research.
Methodological Review A review does not always focus on what someone said [content], but how they said it [method of analysis]. This approach provides a framework of understanding at different levels (i.e. those of theory, substantive fields, research approaches and data collection and analysis techniques), enables researchers to draw on a wide variety of knowledge ranging from the conceptual level to practical documents for use in fieldwork in the areas of ontological and epistemological consideration, quantitative and qualitative integration, sampling, interviewing, data collection and data analysis, and helps highlight many ethical issues which we should be aware of and consider as we go through our study.
Systematic Review This form consists of an overview of existing evidence pertinent to a clearly formulated research question, which uses pre-specified and standardized methods to identify and critically appraise relevant research, and to collect, report, and analyse data from the studies that are included in the review. Typically it focuses on a very specific empirical question, often posed in a cause-and-effect form, such as "To what extent does A contribute to B?"
Theoretical Review The purpose of this form is to concretely examine the corpus of theory that has accumulated in regard to an issue, concept, theory, phenomena. The theoretical literature review help establish what theories already exist, the relationships between them, to what degree the existing theories have been investigated, and to develop new hypotheses to be tested. Often this form is used to help establish a lack of appropriate theories or reveal that current theories are inadequate for explaining new or emerging research problems. The unit of analysis can focus on a theoretical concept or a whole theory or framework.
* Kennedy, Mary M. "Defining a Literature." Educational Researcher 36 (April 2007): 139-147.
All content in this section is from The Literature Review created by Dr. Robert Larabee USC
- Next: Systematic Review >>
- Last Updated: Dec 22, 2022 1:47 PM
- URL: https://guides.lib.odu.edu/literaturereview

IMAGES
VIDEO
COMMENTS
Search. Appraisal. Synthesis. Analysis. Critical review. Aims to demonstrate writer has extensively researched literature and critically evaluated its quality. Goes beyond mere description to include degree of analysis and conceptual innovation. Typically results in hypothesis or mode.
Types of literature reviews Traditional or narrative literature reviews Scoping Reviews Systematic literature reviews Annotated bibliography Developing a search strategy Keeping up to date with literature Where to search Finding a thesis Evaluating sources and critical appraisal of literature Managing and analysing your literature
Examples of literature reviews Step 1 – Search for relevant literature Step 2 – Evaluate and select sources Step 3 – Identify themes, debates, and gaps Step 4 – Outline your literature review’s structure Step 5 – Write your literature review Free lecture slides Frequently asked questions Introduction Quick Run-through Step 1 & 2 Step 3 Step 4
A literature review is a document or section of a document that collects key sources on a topic and discusses those sources in conversation with each other (also called synthesis ). The lit review is an important genre in many disciplines, not just literature (i.e., the study of works of literature such as novels and plays).
There are many types of literature review. The choice of a specific type depends on your research approach and design. The following types of literature review are the most popular in business studies: Narrative literature review, also referred to as traditional literature review, critiques literature and summarizes the body of a literature.
Listed below are definitions of types of literature reviews: Argumentative Review This form examines literature selectively in order to support or refute an argument, deeply imbedded assumption, or philosophical problem already established in the literature. The purpose is to develop a body of literature that establishes a contrarian viewpoint.
Thematic: In this type of literature review, the author will select specific themes that he or she feels are important to understanding a larger topic or concept. Then, the author will organize the sources around those themes, which are often based on relevance or …