Marty wrote on Nov 18
th, 2003 at 12:04am:
George,
One can quibble over whether it is a screening or specific incident but it is closer to the narrow DOE screens than FBI broad screens.
It stands to reason that narrow screens would produce fewer false positives since innocent people are not equally reactive to all accusatory subjects.
Marty,
First, I don't mean to split hairs, but the kinds of polygraph interrogations described in the AP article are quite clearly
screening examanations (about behaviors not known to have occurred).
I am not confident that your second point stands to reason. In either case, the procedure is still without validity. Moreover, significant reactions to relevant questions might be anticipated due to the adversarial, involuntary nature of the interrogations and the fact that the subjects' liberty was at stake. (Indeed, some are still being held prisoner.)
In any event, my point remains that an invalid procedure such as CQT polygraphy would not be expected to result in all persons passing (based on chart readings) when "dozens" of truthful persons are interrogated. There can be little doubt that some other criteria are being relied upon to declare a subject as having "passed" or "failed."
Quote:That said, the very low incidence of positives on DOE screens may well be due to extra-polygraph scoring techniques. Perhaps they put a "fudge factor" in the numerical calculations in favor of the examinee. Do you have any more detail on why this anomoly is?
-Marty
In the counterintelligence polygraph screening programs, it seems that if a subject reacts strongly to a relevant question, he/she gets interrogated, or, as polygraph polygraphers sometimes say, given an "opportunity to explain" their reactions. If the polygrapher(s) involved (and/or their bosses) are ultimately satisfied with the explanation, the subject is deemed to to be "cleared" and "passes." This is discussed in Chapter 2 of
The Lie Behind the Lie Detector (pp. 49-50 of the 3rd ed.) in discussing how 20% of 800 DOE employees polygraphed were initially accused of deception, although all ultimately "passed."
The point I implicitly hoped to make with these posts, and perhaps should now make explicit, is that the DoD's reliance on the polygraph in its hunt for putative weapons of mass destruction seems to be an example of precisely the kind of "belief in its accuracy not justified by the evidence" against which the National Academy of Sciences has warned
(The Polygraph and Lie Detection, p. 219).