Doctor of Social Work (DSW) Research: Literature Review Searches

What are Boolean Operators?

Boolean operators are used by databases to focus searches. Three boolean operators are most recognized by databases: AND, OR, NOT. When using the operators, use them in all CAPS.

AND

• Use AND to tell the database that your search results must include both or all of your keywords
• It helps to narrow your results by combining keywords
• It helps when searching a broad topic, to retrieve fewer results 
• Example: higher education AND online learning will retrieve results that include are relevant to higher education in relation to online learning

OR

• Use OR to connect two or more similar concepts

• It helps to broaden your search and retrieve more results

• When using this operator, not all results will contain both concepts

• Example: online learning OR distance education

NOT

• Use NOT to exclude concepts from your search
• It helps to narrow your search because it excludes concepts
• It tells the database to ignore results related to a keyword
• Example: online learning NOT "graduate school" will retrieve results that are relevant to online learning but exclude all results that are related to graduate school

The Cochrane Handbook for Systematic Reviews of Interventions defines grey literature as "the kind of material that is not published in easily accessible journals or databases". 

The following sources are recommendations. If you are searching only for grey literature in databases, consider limiting your search by "publication type". Grey Literature can include technical reports, annual reports or government publications, etc.