Quote:John Reid, the inventor of the Control Question Test claimed 99% accuracy. This is clearly not accurate. [internal citation omitted]
I am going to nominate this for understatement of the year.
I'm sure Mr Reid didn't really believe his own number; he was just saying that to make his creation look really cool. If perchance he
did believe that it is 99% accurate, he must have been smoking something that'd disqualify him for work even at McDonald's.
Now, I do think that Dr Langan is a bit misleading on the way a CQ test works.
Quote:The assumption is, that if you are prevaricating, the relevant questions will cause a greater response than the control questions. So if the question "Have you ever been late for an appointment?" (control question) elicits less of an emotive response on the polygraph equipment than "Did you murder and rape your girlfriend?" (relevant question) you have failed the test. And, according to the American Polygraph Association (APA) you are lying. Assuming the subject is innocent, it is fairly obvious that he would respond with more emotional autonomic activity to a question regarding a recently deceased loved one than he would an inquiry about punctuality. Obvious to everyone, that is, but the APA.
He neglects to indicate all of the lies and acting that go into this. I don't think "are you punctual" would be used as a CT opposite "did you murder and rape your girlfriend?" (and the word "rape", as I understand it, is far too emotionally charged; it elicits responses even in innocent people, so other, less loaded, terms would be used--but this is a minor point). The polygrapher would make the subject think that if he admits to ever being late to a meeting that they'll assume he did commit the crime, thus heightening the response that the subject will have to the question.
Still, Dr Langan makes some good points and brings together a number of critical comments on the polygraph. An interesting, albeit imperfectly argued, article.