Perceived strengths. The literature review method seeks to identify what has been accomplished previously, allowing for consolidation, for building on previous work, for summation, for avoiding duplication and for identifying omissions or gaps.
Perceived weaknesses. Literature reviews lack an explicit intent to maximise scope or analyse data collected. Any conclusions they may reach are therefore open to bias from the potential to omit, perhaps inadvertently, significant sections of the literature or by not questioning the validity of statements made. Additionally, authors may only select literature that supports their world view, lending undue credence to a preferred hypothesis.
Grant, Maria J., and Andrew Booth. “A typology of reviews: an analysis of 14 review types and associated methodologies.” Health Information & Libraries Journal 26.2 (2009): 91-108.
But there are many types of literature review that can do much more than simply review the literature…so how do you know which one to choose?
In order to decide which type of review to use, you will need to decide what you are trying to do, find out, or achieve.
Trying to develop a new concept? theory? or model?
Then you may want to explore the use of a critical literature review methodology. This methodology allows you to demonstrate how you have not only extensively researched a topic, but that you can critically evaluate the literature and take new conclusions and interpretations from it. You can then present these new interpretations as a new hypothesis or model… sounds good right?
Search
Not systematic – You are searching to find the most relevant stuff.
Appraisal
No need to evaluate quality -You are looking for literature which is fit for purpose.
Synthesis
Usually narrative, but you can be creative with this.
Analysis
Needs to arrive at a new conceptual theory or hypothesis of some kind.
Cautions
Every conclusion you draw will be subjective – Others may not be able to repeat your process
Looking to identify gaps in research?
Then you may want to conduct a mapping review of the literature. This methodology allows you to map out and categorise the existing literature on a topic. From this you can identify what other kinds of reviews or research need doing, as you identify gaps in the literature.
Search
Can be systematic, but searching is usually bound by time constraints, so this can be determined in line with your scope.
Appraisal
No need to evaluate quality
Synthesis
Use tables and graphics
Analysis
Quantify the research found and outline study types – suggest areas of future research.
Cautions
Can be overly descriptive, try to characterise studies on more than the basis of study design
Want to combine statistical data to provide more precise results?
In this case you may consider doing a the meta-analysis (A type of analysis done within a literature review – so really, this is one component of or add on to a systematic review).
Search
Thorough, comprehensive, systematic – Can use funnel plot
Appraisal
Use quality appraisal to guide inclusion/exclusion and/or sensitivity analyses
Synthesis
Use tables, graphics and narrative
Analysis
Analyses measures of effect numerically
Cautions
Your review can only be as good as the included studies allow..also, there is little value in comparing very diverse study types.
Want to combine quantitative with qualitative?
If you want to explore a complex problem using both qualitative and quantitative literature, then a mixed-methods review is for you…
Search
Your strategy must capture both quantitative and qualitative research
Appraisal
Need to use an appraisal tool appropriate for both qualitative, quantitative and/or mixed-methods research
Synthesis
Use tables, graphics and narrative – Present qualitative and quantitative results separately
Analysis
Look for correlations, gaps in the literature and draw conclusions based on combined findings.
Cautions
Theoretical and methodological challenges in bringing together qualitative and quantitative studies
Need to assess what is already known about a topic?
A rapid review is for you.
Search
Determined by time constraints
Appraisal
Formal quality appraisal required
Synthesis
Use tables and narrative
Analysis
Look for directions of effect, and quality and quantity of the literature
Cautions
Doing things quickly…you always run the risk of bias and mistakes are more easily made
Want to know the size and scope of available research?
A Scoping review is for you..
Search
You may want to perform your search as a research in progress
Appraisal
No formal quality appraisal is required
Synthesis
Use tables and narrative.. you can also use commentary
Analysis
Look for directions for future research – Use this to form new research questions.
Cautions
This is not usually a final output…rather a means to an end
Want to address really current matters?
When you want to offer new perspectives on a current issue or point out a new area for further research, you may consider conducting a state-of-the-art review.
Search
Comprehensive and current
Appraisal
No formal quality appraisal is required
Synthesis
Use tables and narrative
Analysis
Present a current state of knowledge and list priorities for future research
Cautions
Beware of subject experts’ particularly idiosyncratic and personal perspectives on current and future priorities.
Want to systematically search for, appraise and synthesis research evidence?
If you are looking to do more than a just review or systematize the literature, then a systematic literature review is for you.
Search
Comprehensive exhaustive and systematic
Appraisal
Formal quality appraisal is required – This can be used to exclude research of poor quality
Synthesis
Use tables and narrative
Analysis
Present recommendations for future research based on what is known, what remains unknown, and what we are still unsure about…The review should answer a broad research question.
Cautions
Adhere to reporting guidelines for a strong output.
Want to create an accessible and usable document in relation to a broad issue?
If you would like to highlight reviews that address interventions and their results in relation to a broad issue, then an umbrella review is for you.
Search
Only searches for component reviews
Appraisal
Formal quality appraisal for reviews is required
Synthesis
Use tables, graphics and narrative
Analysis
Present recommendations for future research based on what is known, what remains unknown, and what we are still unsure about…The review should consolidate all that is known about one broad issue.
Cautions
Requires the pre-existence of the narrower component reviews
Want to know what works, for whom, in what circumstances . . . and why?
If you want to unpack the mechanism(s) of how and why complex interventions thrive or fail, in particular setting(s), then the realist review methodology is for you!
Search
Highly detailed and systematic
Appraisal
Justify how judgments were made
Synthesis
Use tables, graphics and narrative – include information on the constructs analysed and describe the analytic process.
Analysis
Present the key findings with a specific focus on theory building and testing
Cautions
Ensure that the RAMESES (Realist And MEta-narrative Evidence Syntheses: Evolving Standards) guidelines and standards are adhered to for a strong output.
Dr Sally Pezaro 