Device developed by the Johns Hopkins Applied Physics Laboratory, in conjunction with the Lafayette Instrument company, at the request of the US Government in 2005. Its concept of operation is to be used by minimally trained US troops as an initial screening tool in war zones to pare down the number of individuals who would undergo subsequent vetting by the polygraph and other tools. It has two sensors: electrodermal and photoplethysmograph. Test questions are typed into the template of the PDA platform, and the user taps the screen to indicate the place of question onset. The PCASS is a one-chart test that runs about 12 minutes. At the completion of testing an algorithm analyzes the data to produce the screening decision. Five laboratory studies have been conducted with the PCASS using realistic wartime scenarios or mock theft scenarios, with a combined accuracy of 80% when inconclusives were excluded, and about 23% inconclusives. The algorithm was devised to minimize false negatives. The PCASS was approved for use in the Department of Defense in 2007. See: Battelle Memorial Institute (2007); Senter, Waller & Krapohl (2009).
