Databases might have different interfaces but they have similar functionality:
AND: Use AND between search terms to reduce the number of results by including more than one concept, e.g. teen AND pregnancy.
OR: Use OR between search terms to increase the number of results by including synonyms for a concept, e.g. (teen OR adolescent).
" " Use quotation marks to search for a phrase, in the exact order you type it, e.g. “health care reform”.
* Use an asterisk to search for multiple versions of a word, e.g. obes* will allow you to search for obesity and obese.
The American Psychological Association divides research instruments (questionnaires, scales, surveys, tests, etc.) into two broad categories - "published" (commercial) and "un-published" tests.
"Published" tests are generally only available from a commercial publisher for a fee. Indexes like Mental Measurements Yearbook, Tests in Print and the ETS Test Link identify publishers of individual instruments.
"Unpublished" or "Non-Commercial" tests are sometimes reproduced in books or academic journal articles. The library has a number of full-text sources for non-commercial tests.
For more information, see the APA's guide to Finding Information About Psychological Tests.