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Literature Reviews: systematic searching at various levels

This guide briefly looks at some of the different types of reviews to help you determine what kind of review you actually need to do and where to start

Getting Started

This is a brief introduction to some of the different types of literature reviews that you may have to do.

It will not go into lots of detail as there are many online and print resources that cover this topic and which go into a lot more detail than is possible here, but this will hopefully give you some idea as to the type of literature review you're doing as well as provide you with some idea of where and how to start.


If you get stuck get in touch with your academic librarian for support. If you're a PhD student you can also contact the academic research librarians and sign up for their workshops.

A systematic review is different from a literature review in a number of key ways and the table[1] below sets out these differences for you to compare.

Systematic vs. Literature (Narrative) Reviews
  Systematic Review Literature (Narrative) Review
Question Focused on one question

Not limited to focussing on one particular question within a topic; it could be an overview of a topic in a more general way

Protocol A protocol / plan which has been peer reviewed is included No need for a protocol
Background / literature review Provides a summary of the available papers on a / the topic Provides a summary of the available papers on a / the topic
Objectives Any objectives have been clearly documented Identifying objectives is not mandatory
Inclusion / exclusion criteria

Any limiting criteria have been decided on--and recorded in the plan--before the review starts

Limiting criteria are not usually recorded but there are no restrictions on doing so (unless your academic has told you not to)
Search strategy

The search strategy should be comprehensive covering key databases and other relevant resources.

Separate searches should be done for each database and the search strategy and the outcomes should be recorded in a clear, systematic, and logical way to make them as repeatable as possible.

The search strategy is not usually recorded but there are no restrictions on doing so (unless your academic has told you not to)
Selecting articles (process) How articles were selected for inclusion should be clear and understandable How articles were selected for inclusion is not usually described
Evaluating articles (process) The evaluation of each study should involve a comprehensive assessment of their quality, strengths and weaknesses An evaluation of the quality of each study might not be included.
Extracting key information The process should be clear and specific so it could be followed by someone else (e.g. the 2nd person in a 2 person systematic review) How the key information was extracted from the papers is not usually recorded in an explicit, step-by-step way
Results and synthesising the data

There should be clearly written summaries which have been based on high-quality evidence.

Any methods used for synthesising the data and presenting the results should be done in such a way as to minimise bias.

Summaries can be based on papers where the quality of the studies may not have been examined.

Instances of possible bias are less likely to have been dealt with


[1] Adapted from:

Bettany-Saltikov, J. (2012) How to do a systematic literature review in nursing: a step-by-step guide. Berkshire: Open University Press.

Robert Gordon University Library, Aberdeen (2020) Systematic reviews: examining myths & misconceptions. Available from: (Accessed: 03 August 2021)