If ever there was a maze of terminology, then the realm of literature review types is one. It seems that lecturers, supervisors, and journals in specific disciplines may all mean slightly different things when they label types.
Obvious advice is to check expectations and use readily available checklists and templates for essential parts to include (e.g. for scoping reviews see JBI’s template and the PRISMA ScR checklist; there are links to nice examples from different disciplines in Snyder (2019). By doing this kind of checking, we can determine if specific parts and steps are required, such as whether we need to appraise the quality of literature that has met our eligibility criteria or not.
Ok, there are a lot of resources, but how do we choose a type?
To find a pathway through the maze, we think there are three main considerations:
- The extent to which our research question is broad or narrow;
- The extent to which our eligibility criteria for studies that we include or exclude are broad or narrow;
- Our reason for doing the review.
A topology of systematic reviews of literature
We’ve put the first two considerations together to form a topology for a sample of review types.
Following the clines in the topology, we can say that i) systematic reviews tend to have narrower research questions and narrower eligibility criteria compared to integrative reviews, and ii) scoping reviews tend to have broader research questions than the other two types.
What these three types have in common is that researchers are expected to follow an exact, replicable process for conducting their review. This requires us to show the process of how literature is searched for, sifted through, and analysed. This careful documentation and visible sharing of the ‘behind the scenes’ process is not required of narrative literature review types. (If you are keen to know more about review types, check out Grant and Booth (2009) for their interpretation of 14 review types in health-related literature.)
Broader to narrower research questions
For developing our research questions and deliberately making them broader or more narrow, we can apply models, such as PICo:
Broader to narrower eligibility criteria
For developing eligibility criteria, we can have a lower or higher number of criteria, such as deciding whether we will include specific locations, languages, participant attributes, studies with specific research methodologies, and publication types, etc. Then, we can broaden or narrow each distinctive kind of eligibility criteria. For example, for publication types, we may choose to only include peer reviewed journal articles, or broaden to theses and dissertations, reports, etc. We always need to have a justification for what is in or what is out.
Common overarching reason
A common overarching reason for doing some form of review is to create a discrete research output that serves as a stepping stone into a new research project. For example, a research group of nurse educators undertook ‘a qualitative meta-synthesis’ of literature about student experiences in a graduate entry nursing programme. Findings from that review were used as stepping stone for more specific areas of investigation, such as a longitudinal case study about students’ well-being. The introduction of their case study research links back nicely to findings from their review.
More specific reasons
Unfortunately, for those of us trying to choose a literature review type, it is not as simple as matching one reason with one review type. Indeed, as we read examples that are relevant to our own areas of research, we can find a lot of cross-over with the rationale that researchers provide. There is, however, a close relationship between reasons and the parameters of our research questions and eligibility criteria. See a few examples in Figure 2.
If our goal is to make specific recommendations for policy and practice, then that necessitates a specific research question and very specific eligibility criteria (as is often the case for a systematic review). Those choices enable us to clarify what we are making recommendations about and for what exact context. Alternately, if we want to evaluate current knowledge about something and pull together a wide range of sources and wide range of research methodologies, then our eligibility criteria are likely to be broader (as may be the case for an integrative review). Or, our inquiry might be about a phenomenon that is less well defined and we need a broader research question to establish existing knowledge and clarify key concepts (as may be the case for a scoping review).
So by checking expectations and resources, clarifying why we are doing a review, and giving some careful thought to the breadth and degree of specificity of our inquiry, we can settle on a review type and go for it.
Resources for further learning:
- Related Te Mātāpuna Library workshops for AUT students
- Recommended reading (search through Te Mātāpuna Library for free access)
Acknowledgements
Lucy would like to thank her Te Mātāpuna Library colleagues at AUT, particularly Dr Josta Heyligers for initial development of an SRL workshop and feedback on this blog. With Dr Andre Breedt, we collaborated, as three amigos, to devise a topology for explaining the gist of key choices.
