Literature Review: Theoretical Background
There are various types of literature reviews. Below is an overview of the main types:
A systematic review evaluates all existing literature that addresses a specifically formulated research question. It aims to provide the best possible answer based on available evidence. It involves a thorough statistical analysis of existing publications, conducted according to strict procedures, using an explicit method of identification and selection, which is also clearly explained in the publication. The main question driving the review must be clearly formulated.
A systematic review is carried out according to a specific procedure consisting of eight steps:
- defining the research question
- writing a protocol
- searching for publications
- selecting publications
- extracting data from publications
- assessing the quality of studies (bias risk assessment)
- synthesizing data (synthesis or meta-analysis)
- drawing conclusions and discussion.
Guidelines for systematic reviews can be found with Cochrane (medical sciences), Campbell Collaboration (social sciences), PRISMA, and RAMESES. Systematic reviews must be registered, which can be done on the Prospero, Campbell, and Cochrane Library.
A narrative review is a form of critical summary and comparison of existing publications. It brings together various theoretical approaches or debates from previously published research. The narrative review leads to the identification of questions that still need to be answered. A narrative review can focus on different aspects of research: theory, methodology, or chronology of existing research. Theoretical and methodological approaches guide the researcher to conclusions about new theories and methodologies that could be applied to answer certain research questions. A chronological approach is intended to document the development within a specific field.
A scoping review is conducted to map the scope, characteristics, or extent of existing literature, crucial concepts and terms, evidence, and methodologies used in a given research field. These reviews are sometimes called “mapping reviews.” The aim is to identify potential research questions.
A rapid review is a quick processing of literature without strict guidelines or protocols. It is less exhaustive and also takes less time.
A review of reviews is a report on other reviews, without primary literature.
A meta-analysis is a recalculation of existing clinical studies. It involves a statistical analysis, with an approach similar to that of a systematic review.