Narrow the search
Broaden the search
Wildcard (*): find all forms of a term
Quotes ensure search of exact phrase
Parentheses (): ensure all terms searched as set
The number of left parentheses must be equal to the number of right parentheses to avoid search errors or unintended search strategies.
(X AND Y) OR Z
X AND (Y OR Z)
Avoiding (or minimizing) the use of the NOT operator can be beneficial as well. A misplaced parenthesis can change a search.
(X NOT Y) OR Z
X NOT (Y OR Z)
(X AND Y) NOT Z
X AND (Y NOT Z)
((X OR (Y AND Z))
((A AND B) OR C)
(J OR (K AND L))
Could be rewritten as:
((X OR (Y AND Z)) AND ((A AND B) OR C) AND (J OR (K AND L))
Possible search results could include:
As social and cultural norms change, so does the vocabulary. When searching for older items in databases, some searches require use of antiquated, non-standard, exclusionary, and potentially offensive terms.
An example might be searching "ill housed persons." In PubMed/Medline, research related to "ill housed persons" from 1966 to 1985 was cataloged using the MeSH term "transients and migrants." If historical material was being sought and if the antiquated terms were not included, the search strategy could have missed relevant material.
The University of Michigan Library has initiated a project to address these concerns and provides suggested wording to use.