"A research instrument is a testing device for measuring a given phenomenon, such as a paper and pencil test, a questionnaire, an interview, a research tool, or a set of guidelines for observation."
Mosby's Dictionary of Medicine, Nursing & Health Professions, p. 1605, W 13 M8933 2009 REFERENCE.
What is the difference between a "published" and an "unpublished" test/research instrument?
Book indexes to published tests:
Book indexes to unpublished tests: