Research Portal

Before you can begin a literature (or narrative) review, you must decide its purpose.

• Are you attempting to give an overview of the current research on a topic?
• Do you want to address areas that need more research?
• Are you looking to synthesize the research and come up with a model or hypothesis based on current research?

In general, a lit review is a carefully designed overview, summarizing and synthesizing a topic or research question. The purpose determines how rigorous and comprehensive your search needs to be in order to conduct a high quality literature review.

Types of Literature Reviews:

• Narrative Review: attempts to give an overview of the current literature, may cover a wide range of topics, usually is chronological.
• Scoping Review: preliminary assessment of the research literature on a specific topic; used to identify the nature and extent of the available evidence.
• Rapid Review: a rigorous "review of reviews" on a focused question, with less sophisticated search strategies and quality appraisal than a full systematic review.
• Critical Review: a critical analysis of the research literature from which the authors derive a hypothesis or model.

1. Define your research question
   • what is your topic; is it manageable;
2. Determine inclusion/exclusion criteria
   • what makes a study relevant to your topic or not;
3. Choose appropriate databases
   • identify and search appropriate ones depending on the scope of your review;
4. Keep track of your searches
   • Record each database and your search query (terms);
5. Review and synthesize the studies you find
   • take notes as you read the articles/studies;
6. Be on bias alert!
   • scrutinize the methodology section author affiliations.

Identify inclusion and exclusion criteria! They help you determine study relevancy and also minimize/eliminate bias when carefully considered in conjunction with a well thought out research question.

Inclusion criteria must be present in order for a study to be included in the review, for example:

• Studies must report experimental outcomes.
• Studies must include comparison data.
• Studies must identify specific controls.
• Studies must be published within 5 years (choose a date range that fits your research question).

Exclusion criteria exclude a study from the review for example:

• Studies that are more than 10 years old (select a date range that fits your research question).
• Studies that only include observational, not experimental, data.
• Studies published in a language other than English

Reporting bias can occur when the results of a review are influenced by where or how the review is published.

In your literature review, be aware of the types of bias!

Cochrane provides a list and description of the major forms of reporting bias such as:

• Publication bias
• Time lag bias
• Multiple publication bias
• Location bias
• Citation bias
• Language bias
• Outcome reporting bias