Reviewing the Literature: Levels of Evidence
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Types of Reviews
There are many different types of literature reviews from the traditional literature review to the rigorous systematic reviews. Each has its own methodology. Please consult your thesis supervisor to decide on the type of review best fitting your research question.
- Types of Literature ReviewsAn overview of many types of reviews from the University of Toronto.
- Study DesignsAn exhaustive guide reviewing the various types of study designs and literature reviews in health sciences from RBHS. Browse links to sub pages on types of studies, including differences, and comparisons.
Literature Review Tutorials
- Nutrition: Literature ReviewsA guide from UNC Chapel Hill on how to write literature reviews in nutrition. Includes a 10-page handout and links to many resources.
- Nutrition: Writing a Literature ReviewA short overview from WestChester University Libraries.
- Learn how to write a literature reviewDetailed description of each component of a literature review from the Writing Center of the University of Wisconsin.
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Literature Reviews: An Overview for Graduate StudentsVideo from NCSU(9:38 min), general topics.
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Social Work Literature Review GuidelinesA one-page summary from Purdue OWL.
What is PICO?
What is PICO(T)?
PICO is a tool commonly used in medical and health research to help researchers formulate a question. The difficulty in creating a question is often underestimated and PICO can help us parse out the important keys a good question should contain. This is just a tool, not a rigid structure in which all questions must fit.
P = Patient, Population, and/or Problem
I = Intervention
C = Comparison (not always applicable)
O = Outcome
T = *Type of Study (what study design is most appropriate to answer the question?)
Sometimes you will see PICO TT where the additional T stands for the type of question you are asking which you do need to know to determine the best study design.
*In some PICO(T) models you will see T stand for time. This only works if your question includes a concept of time.