Systematic reviews, scoping reviews and meta-analysis
Writing a literature review for postgraduate research starts with choosing the right approach. The type of review (systematic, scoping, or meta-analysis) shapes the process. This page explains the key differences between these review types and provides practical structures and examples to guide your work.
While there are similarities between these three review types, there are also significant differences.
Different types of reviews
A literature review focuses on elucidating a research gap and comparing and contrasting studies that relate to it.
A scoping review is written to map key concepts and evidence, ascertain the breadth of a field of research and to inform future research. A scoping review might outline a broad research question as a precursor to posing a narrowly focused research question in a systematic review later. Typically, however, it outlines objectives in an aim statement.
A systematic review is written to answer a specific research question. While the reasons for writing a systematic review differ, the research question is central.
A meta-analysis uses statistical methods on data from several homogeneous quantitative studies in order synthesise the results of those studies.
All types of review:
- are planned carefully with either the research question/ hypothesis or key concepts/ evidence in focus
- involve discrete stages or steps
- compare and contrast primary or secondary research
- are clearly structured with no extraneous sections; everything discussed is tied to its purpose
- narrow in focus from broadly related literature to increasingly specific details drawn from the literature, which is sometimes informally called the ‘eye of the storm’ in a review paper
- are written with clarity and economy, and precise, complete sentence structure
- use academic writing style and pay attention to unity and coherence in terms of paragraph structure
- must clearly elucidate:
a) the research gap (literature review)
b) the key concepts and evidence (scoping review)
c) an answer to a specific research question (systematic review); or
d) statistical evidence from a synthesis of homogeneous quantitative studies (meta-analysis).
Structure of a review
A review typically follows the proforma structure provided by JBI, PRISMA, or Cochrane (Tricco et al., 2018). Use the proforma as a guideline – you need not follow it prescriptively.
The proforma is essentially the same format as an empirical or scientific report, otherwise known as an AIMRaD report after its main sections: Abstract, Introduction, Methods, Results and Discussion. While it is the same structure as a typical scientific research paper, there are inclusions specific to reviews in some sections.
A structured abstract is usually written for a scoping or systematic review. This is an abstract written with section headings for each part.