There are a number of different types of literature review. Common types include:

• literature review
• scoping review
• systematic review
• narrative review
• meta-analysis, and
• rapid review

This guide focuses on general principles that apply to conducting a good-quality literature or narrative review.

For information on systematic reviews and scoping reviews see the Systematic Reviews tab or the VU Systematic Literature Reviews guide.

A literature review can be defined as:

A critical summary and assessment of the range of existing materials dealing with knowledge and understanding in a given field … Its purpose is to locate the research project, to form its context or background, and to provide insights into previous work

(The SAGE Dictionary of Social Research Methods, 2006)

• A literature review involves defining the topic, identifying sources, evaluating the sources, synthesising and reporting.
• Aims to provide the author with a solid understanding of the key principles and theories in their chosen subject area
• Aims to identify what is already known, and to identify gaps in the evidence base to provide a starting point for new research
• The key element of any literature review is a critical analysis or assessment of the literature.

Common goals include:

• Consolidating dispersed primary literature into a coherent overview of the current state of knowledge on a topic.
• Identifying central issues and discovering unresolved questions (gaps in the literature)
• Identifying next steps for future research
• Resolving conflicts (for example, why an effect is found in some studies but not others)
• Drawing links across separate fields (for example, demonstrating that two lines of research are investigating a common phenomenon)

Adapted from:

Salkind, N. J. (2010). Encyclopedia of research design. SAGE Publications Ltd

1. Defining the review topic or question

2. Locating sources

3. Judging the quality of studies identified

4. Synthesising the studies identified

5. Reporting the findings of the review

While the stages are presented as a linear process, most ‘real world’ reviews do not follow a simple progression through stages 1 to 5. Doing a literature review should be an iterative process and searching should continue throughout  the review process as the reviewer develops a closer understanding of the topic.

Tips:

Determine what it is you need to know – ask yourself a few questions while you are reading abstracts or summaries of each article or information source you find. This can help you decide whether or not a source is relevant to your research or if you need to broaden or narrow your focus.

Once you have read through a few items, look for trends and related subjects or topics within the research - ask yourself again what you need to know and start setting up a framework which will assist you to find the information you need.

In the early stages of the literature review, it is common to find your interest in specific areas change as you start reading the literature. Be flexible in the early stages when reading relevant articles and be prepared to revise any specific objectives for your review.

During thesis research you usually spend some time clarifying the specific areas of focus for a review. During the early stages of reading relevant literature, a good strategy is to note emerging themes and ideas, and develop and revise a set of specific questions, or sub-topics to create an overall framework for the review.

A useful tool for this early stage of exploring themes and ideas is mind-mapping. This can be done with pen and paper, or there are online equivalents that offer extra functionality. Consult the Literature Review Toolbox section of this guide for more information.

Adapted from: Doing a literature review. (2010). In Thomas, D. R. & Hodges, I. D. Designing and managing your research project: Core skills for social and health research (pp. 105-130). 

Consider factors that will influence the scope of the review, such as:

• Will it have a local, national or international focus?
• What is the time period?
• Will you include only research publications? Or will grey literature such as government reports or policy documents also be included ?
• Will you focus on specific types of research methods?  
• Will you focus on a particular research theory? Or will you look at multiple theoretical perspectives?
• Will your review focus on studies on human subjects only, rather than animals?  Will you focus on a particular age range?

Be sure to note down all the details of the scope as part of your project plan. These details should be included in the introduction of the review.