Ambulatory biosensor assessment includes a diverse set of rapidly developing and increasingly technologically sophisticated strategies to acquire minimally disruptive measures of physiological and motor variables of persons in their natural environments. Numerous studies have measured cardiovascular variables, physical activity, and biochemicals…

Fifty years ago, L. J. Cronbach and P. E. Meehl (1955) advocated for the concept of construct validity, noting that psychologists study hypothetical, inferred entities and that validating measures of such entities involves basic theory testing. Three important developments in clinical assessment following that seminal article are noteworthy.…