High Quality Content by WIKIPEDIA articles! In contemporary research and clinical practice, Robert D. Hare`s Psychopathy Checklist-Revised (PCL-R) is the psycho-diagnostic tool most commonly used to assess psychopathy. Because an individual`s score may have important consequences for his or her future, and because the potential for harm if the test is used or administered incorrectly is considerable, Hare argues that the test should only be considered valid if administered by a suitably qualified and experienced clinician under controlled and licensed conditions. Hare receives a royalty on licensed use of the test.