Even if you are not performing a full systematic review, drafting a protocol (a detailed plan of your study) before you begin any type of literature review ensures reproducibility, transparency, and reduces bias. Follow these steps to construct a plan for your literature review—and remember to keep a record of all your hard work using some type of research log.
1. Write out your review question & identify the key concepts in your review question
A. Draft a clearly defined question that you will answer with this review of the literature
Example: Does sugar-sweetened beverage consumption affect obesity in children?
B. Identify the key concepts in your review question--for health questions, consider using the Population, Intervention, Comparison, Outcomes, Study design (PICOS) framework to list your key concepts. If your review question doesn’t fit nicely into “PICOS,” simply list the most important elements of the question.
Example: Does sugar-sweetened beverage consumption affect obesity in children?
Population: Children
Intervention: consuming sugar-sweetened beverages
Comparison: non-consumption of sugar by children
Outcome: obesity
2. List synonyms for each of your key concepts
Brainstorm different terms or phrases that authors may use to describe your key concepts across the research literature. Keep track of all this in your research log—you will probably add to the list after starting to search the literature.
Example: Obesity, obese, overweight, weight gain (and possibly others)
Sugar sweetened beverages, soda, soft drinks, pop (and possibly others)
Children, youth, child, minor, preschool, school aged (and possibly others)
3. Determine your sources for evidence gathering
Decide which (and how many) scholarly databases you will search, and determine if you will also search for gray literature (including dissertations).
Example: PubMed, PsycINFO = scientific scholarly literature; Web of Science = interdisciplinary scholarly literature
4. Develop a search strategy for each database you plan to search
• Follow Boolean logic (combine key concepts with AND; combine synonyms with OR)
• Use truncation and proximity operators as necessary (like the * in the example below)
• Keep in mind that you will need to make adjustments in your search strategy for each database you search.
• Look in the help section of each database you search for detailed instructions on constructing your search.
5. Determine which studies to include (and exclude), and why
Consider how you will decide which studies to include in your review. List your inclusion criteria here. Hint: your reasons for inclusion should mirror your PICOS’s elements/key concepts.
Example: Included studies must
1. Be about children between the ages 6-12
2. Focus on consumption of sugar-sweetened beverages
3. Focus on obesity
4. Be a primary study (not a review article)
6. Perform your search, & use a citation manager to track & critique results
While not required for your review, a citation manager will make the process of organizing and writing your literature review MUCH easier. Sacramento State University provides Endnote to current students, staff, and faculty. (search the Sac State IRT Software Catalog and scroll down to ‘Endnote’). You can send citation management questions to the library by contacting our librarians: https://csus.libguides.com/Endnote.
For a more detailed exploration of using citation management tools for your review, see https://guides.library.cornell.edu/evidence-synthesis/citation-management
7. Appraise the quality of studies you’ve chosen
Determine the methodological quality of your studies, assessing their relevance and results--are they are believable and useful? For most every field, there are critical appraisal tools (CATs) and related worksheets and guides.
8. Extract data
Establish a regimented approach to extracting data from the studies you have included, and provide a narrative synthesis of your findings. Consider Google Forms, Excel, or Qualtrics for data extraction.
9. Write up your literature review methods such that others could repeat the process
Briefly summarize steps 1‐10, listing databases searched and the eligibility criteria that you applied. Include a full copy of your search strategy in an appendix or as a table in your write-up. If you kept track of everything using a protocol or research log, you will have all this information ready to go.
10. Send us your questions—if you are working with a librarian, feel free to reach out to them directly via their Sac State email.
