Objective Assessment in Clinical Psychological Science: Progress in Wearable Alcohol Biosensors.

Clinical psychology is a discipline reliant on self-reports but uniquely susceptible to specific biases associated therewith. Here we provide a prototype for objective behavioral assessment drawn from the field of alcohol science, describing an emerging class of wearable transdermal biosensor. We note the challenges of transdermal alcohol assessment and describe recent performance gains from updated devices and machine learning analytic tools. We indicate unanswered questions for transdermal technology, including device longevity and the accuracy of devices for producing fine-grained estimates of drinking quantity. We identify factors that can impede development of transdermal sensors and other new objective measures, including the tendency to judge new tools against an implicit ideal, and consider scientific findings divorced from methodology. Finally, in evaluating novel objective measurement tools, we argue for careful consideration of not only error magnitude but also error type (i.e., random versus systematic), identifying measurement diversification as a priority for clinical psychology moving forward.