What exactly will you cover in your review?
How comprehensive will it be?
How long? About how many citations will you use?
How detailed will it be? A review of ALL relevant material or will the scope be limited to more recent material, e.g., the last five years?
Are you focusing on methodological approaches; on theoretical issues; on qualitative or quantitative research?
Will you broaden your search to seek literature in related disciplines?
Will you confine your reviewed material to English language only or will you include research in other languages too?
Create a well-built research question. This:
starts your entire search process
provides focus for your searches
guides the selection of literature sources
Question formats are helpful tools researchers can use to structure a question that will facilitate a focused search. Such formats include: PICO, PEO, SPIDER, and COSMIN. Other formats can be found here.
The PICO format is commonly used in evidence-based clinical practice. This format creates a "well-built" question that identifies four concepts: (1) the Patient problem or Population, (2) the Intervention, (3) the Comparison (if there is one), and (4) the Outcome(s).
Example: In adults with recurrent furunculosis (skin boils), do prophylactic antibiotics, compared to no treatment, reduce the recurrence rate? (Cochrane Library Tutorial, 2005)
| P | adults with recurrent furunculosis |
| I | prophylactic antibiotics |
| C | no treatment |
| O | reduction in recurrence rate |
The PEO question format is useful for qualitative research questions. Questions based on this format identify three concepts: (1)Population, (2) Exposure, and (3) Outcome(s).
Example: In infants, is there an association between exposure to soy milk and the subsequent development of peanut allergy (Levine, Ioannidis, Haines, & Guyatt, 2014)?
| P | infants |
| E | exposure to soy milk |
| O | peanut allergy |
The SPIDER question format was adapted from the PICO tool to search for qualitative and mixed-methods research. Questions based on this format identify the following concepts: (1) Sample, (2) Phenomenon of Interest, (3) Design, (4) Evaluation, and (5) Research type.
Example: What are young parents’ experiences of attending antenatal education?
| S | young parents |
| P of I | antenatal education |
| D | questionnaire, survey, interview, focus group, case study, or observational study |
| E | experiences |
| R | qualitative or mixed method |
Search for (S AND P of I AND (D OR E) AND R) (Cooke, Smith, & Booth, 2012).
The COSMIN (COnsensus-based Standards for the selection of health status Measurement INstruments) format is used for systematic review of measurement properties. Questions based on this format identify (1) the construct or the name(s) of the outcome measurement instrument(s) of interest, (2) the target population, (3) the type of measurement instrument of interest, and (4) the measurement properties on which the review focuses.
Visit the COSMIN website to view the COSMIN manual and checklist.
As literature reviews may already exist on some aspect of your topic, it is often useful to search databases for them. However, while many databases do not permit one to limit to the specific document type of literature reviews, some do.
If you are searching for literature reviews in a database, like Academic Search Complete or CINAHL, it is usually a good idea to enter the particular search term(s) for your topic in the first search box and then "literature review" in the second search box.
Below is an example of what that could look like.
Note: If you add an asterisk * to the end of 'review', your search will retrieve both literature review and literature reviews.
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