



DACA Deputy Director Donald Krapohl (MSNBC)



It should be borne in mind by soldiers in the field who are being asked to rely on the PCASS that those responsible for developing it, including most visibly Don Krapohl, who has been know that PCASS is highly unreliable and have deliberately overstated its accuracy. (In addition to his appearance in the video segment of the Weekend Edition on Saturday, 12 April.)



DACA avoided testing PCASS under anything approaching field conditions. The same methodology that was recently used in a field study that found voice stress analysis technologies to be



DACA also avoided testing PCASS in situations with a low base rate for deception (such as in screening for spies, terrorists, and saboteurs), preferring instead to conduct its studies in settings with an unrealistically high base rate of deception of 50%. Krapohl and others at DACA know full well that if a lower and more realistic base rate of deception, say as high as 5% were used, PCASS's evident performance as a screening tool would appear much worse, the high number of false positives making the few true positive results of little practical use. Why didn't DACA test PCASS under realistic base rate conditions before issuing it to our troops?



And DACA avoided testing PCASS's robustness against countermeasures, despite knowing full well that



As Bill Dedman of MSNBC pointed out in his report, DACA is deliberately overstating PCASS's performance in the unrealistic laboratory tests to which it was subjected by omitting inconclusive results when calculating its accuracy. There is no scientific ground for doing this: it's willful fraud. DACA is lying to the American people, and to our troops. DACA is touting an accuracy rate of 82-90% based on (again, unrealistic) laboratory studies. But the true accuracy rate based on those studies is only 63-79%. Under field conditions, with realistic base rates, and with subjects knowledgeable about countermeasures, much lower accuracy rates than this latter range of 63-79% can be reasonably expected. And DACA knows this.



As a former soldier, interrogator, and linguist, I'm outraged that DACA is foisting this rubbish on our troops. I encourage all to tell your friends, relatives, and acquaintances in the armed forces about the It should be borne in mind by soldiers in the field who are being asked to rely on the PCASS that those responsible for developing it, including most visibly Don Krapohl, who has been DACA 's media front man for it,and have(In addition to his appearance in the video segment of the MSNBC report , Krapohl was also interviewed on National Public Radio'son Saturday, 12 April.)DACA avoided testing PCASS under anything approaching field conditions. The same methodology that was recently used in a field study that found voice stress analysis technologies to be no better than chance could have been used to test PCASS. Why didn't DACA do so before giving PCASS to our troops?DACA also avoided testing PCASS in situations with a low base rate for deception (such as in screening for spies, terrorists, and saboteurs), preferring instead to conduct its studies in settings with an unrealistically high base rate of deception of 50%. Krapohl and others at DACA know full well that if a lower and more realistic base rate of deception, say as high as 5% were used, PCASS's evident performance as a screening tool would appearworse, the high number of false positives making the few true positive results of little practical use. Why didn't DACA test PCASS under realistic base rate conditions before issuing it to our troops?And DACA avoided testing PCASS's robustness against countermeasures, despite knowing full well that Al-Qaeda and Iraqi insurgents have studied them, and any operatives sent to infiltrate U.S. installations, knowing that they're going to be tested either by polygraph or PCASS, are likely to learn how to fool such tests . Why didn't DACA test PCASS against countermeasures before issuing it to our troops?As Bill Dedman of MSNBC pointed out in his report, DACA is deliberately overstating PCASS's performance in the unrealistic laboratory tests to which itsubjected by omitting inconclusive results when calculating its accuracy. There is no scientific ground for doing this: it's willful fraud. DACA is lying to the American people, and to our troops. DACA is touting an accuracy rate of 82-90% based on (again, unrealistic) laboratory studies. But the true accuracy rate based on those studies is only 63-79%. Under field conditions, with realistic base rates, and with subjects knowledgeable about countermeasures, much lower accuracy rates than this latter range of 63-79% can be reasonably expected. And DACA knows this.As a former soldier, interrogator, and linguist, I'm outraged that DACA is foisting this rubbish on our troops. I encourage all to tell your friends, relatives, and acquaintances in the armed forces about the MSNBC report on PCASS and the commentary here.