Your selection criteria will be determined by your research question
Decide the types of sources you are going to include and exclude
Think about any additional limits to your criteria, (language, publication type, study design, etc.)
Also think about how you will select certain studies and not others
Search Strategy
Choose the databases that you will search
Identify key terms for your research question along with synonyms, narrower terms, and broader terms.
Try different combinations of the terms you identified to do some preliminary searching. Keep track of what terms you use and how effective they are (see Document the Search).
Widen or narrow your search depending on the results you are getting. If you are not finding any useful results, try brainstorming different key words.
Once you find a highly relevant article, pay attention to the terms it uses to describe key concepts. These can be used to search for further relevant results. You can also use the article to look backward and forward.
Looking backward: read the literature review in the article. See what/who is referenced and look at some of their articles.
Looking forward: Use a citation index such as Web of Science or Google Scholar to see who has cited the article.
Document the Search
Understand which searches are effective and which are not.
Keep from repeating searches.
Conduct a thorough search.
How to document
Use a tool you're comfortable with such as spreadsheet software (Microsoft Excel, Google Sheets) or a word processor (Microsoft Word, Google Docs).
At a minimum, you should note: the database you used, the search terms, the filters, and number of results.
Use a citation manager like Mendeley to keep track of sources.
