QuoteThus, Polygraph is used as a interrogation tool (could be done this way even if the machine is turned OFF) not a scientific test at all since the examiner has NO idea whether the examinee is lying, not until he actually confesses believing the scam, that the Polygraph machine will expose his lie or even what the examiner would consider a lie.
Many have failed telling the "examiner" what they though he wanted to hear due to berating pressure.
Quote from: opjt123 on Sep 20, 2008, 07:09 AMFrom the polygraph operator's perspective, the rationale for the probable-lie "control" questions is to get the examinee to answer a question untruthfully, or at least to make the examinee have doubts as to whether his answer is completely truthful. The polygrapher then uses reactions to the control questions as a basis of comparison with any reactions to the relevant questions (the ones that are truly of interest).
"Did you ever cheat in school?" is an example of a commonly used control question. It is assumed that everyone has. (Not a safe assumption, I think.) But in any event, the polygrapher will try to convince the examinee that cheating in school is a very bad thing, and anyone who would do such a thing would not be a suitable candidate for hire. The idea is to pressure the examinee to answer that question "no."
If the examinee answers "yes," then the polygrapher will likely feign an attitude of deep concern, ask about precisely when and where the examinee cheated, and perhaps make a show of writing down the details. Then, the polygrapher may remind the examinee that his agency considers the honesty and integrity of its employees to be of paramount importance and ask, "Other than what you told me, did you ever cheat in school?" At this point, the examinee will likely answer "no." If the examinee still answers yes, the process of interrogation will be repeated until the examinee answers "no."
This final "no" will still be considered a probable-lie, and reactions to it will be compared with reactions to a relevant question such as, "Did you ever commit a major undetected crime?" The key to passing is to show a stronger reaction to the control question than to the relevant question, and countermeasures can help to achieve this result.
For more about control questions and countermeasures, see chapters 3 and 4 of The Lie Behind the Lie Detector:
https://antipolygraph.org/lie-behind-the-lie-detector.pdf