Humor researchers use instruments to assess individual differences in humor, to display a person’s humor profile, to relate these differences to other phenomena (like personality or health), and to document changes in humor due to interventions. The question of what instrument to use arises. Is it one for all research questions? Is it the one with the highest number of subscales or the most recent one, the one with the most sophisticated name? Several formal-and content-related factors determine the choice of which instrument to use for what purposes. This entry first discusses the criteria used to determine if a test is psychometrically sound. Second, currently used humor instruments (joke/cartoon tests and questionnaires) are presented.