This guide is designed to provide you with an overview of various types of literature reviews/syntheses, with a particular focus on systematic reviews. Many of the systematic review resources will also be useful for other types of reviews.
The articles below describe different types of literature reviews and methods of synthesizing scientific literature. These articles can be very helpful when you are trying to decide what kind of review best suits your goals.
Also referred to more generally as literature reviews. This kind of review examines the current literature on a topic at various levels of completeness and comprehensiveness. The type of topic for this kind of review is wide-ranging. Narrative reviews often do not report the literature search methodology and do not typically include statistical analysis, but rather tend to provide a narrative synthesis.
"Seeks to systematically search for, appraise and synthesis research evidence, often adhering to guidelines on the conduct of a review" (Grant & Booth, 2009, p.95) Systematic reviews can synthesize quantitative, qualitative or a combination of qualititative and quantitative literature.
In a systematic review methodologythe following steps are taken in a rigorous, systematic and transparent manner:
define a clear and answerable research question
develop and conduct a comprehensive literature search
select and document studies to be included/excluded
assess quality and bias
synthesize and analyze data
Scoping reviews are relatively new and do not yet have a clear definition, although the steps are very similar to those of a systematic review. Here is a flavour for some of the definitions...
"Definitions commonly refer to ‘mapping,’ a process of summarizing a range of evidence in order to convey the breadth and depth of a field. Scoping studies differ from systematic reviews because authors do not typically assess the quality of included studies [3-5]. Scoping studies also differ from narrative or literature reviews in that the scoping process requires analytical reinterpretation of the literature." (Levac, Colquhoun & O'Brien, Implementation Science 2010, 5:69)
"The ‘scoping’ study comprises a further type of literature review, [...] So what might we consider to be the main differences between a systematic review and a scoping study? First, a systematic review might typically focus on a well-defined question where appropriate study designs can be identified in advance, whilst a scoping study tends to address broader topics where many different study designs might be applicable. Second, the systematic review aims to provide answers to questions from a relatively narrow range of quality assessed studies, whilst a scoping study is less likely to seek to address very specific research questions nor, consequently, to assess the quality of included studies." (Hilary Arksey & Lisa O'Malley, International Journal of Social Research Methodology 2005, 8:1, 19-32)
Networks of researchers, professionals, patients, and people interested in health or education have formed international collaborations to improve the quality of systematic reviews and support dissemination of the results. The three key collaborations are: