Abstract

The use of tests and measures to understand our patients is one of the hallmarks of applied psychology. Unlike the practices of psychiatry, social work, and other allied mental health disciplines, psychologists rely on measurement to quantify patient cognitive functioning, psychopathology, behavior, strengths, neuropsychological performance, aptitudes, attitudes, and social contexts. Following the empiricist’s creed, much of applied psychological assessment rests on the assertion of Thorndike (1918) that “whatever exists at all exists in some amount” (p. 16).