While watching Dr. Phil yesterday, I saw a polygraph examiner who couldn't see that the alledged child molestor was manipulating the test results. Using bio-feedback, I can, and have, rendered a polygraph useless by creating sharp reactions to all questions asked of me from "Is your name Meg?" to "Did you do the crime that you've been accused of?"

I couldn't believe that the examiner hadn't come across that before. The ease with which I can evoke a "inconclusive" result is so very simple that I cannot believe that others haven't figured it out before. 

Meg

Meg wrote on Apr 5^th, 2007 at 6:20pm:


Here's the problem with an inconclusive polygraph: it doesn't get you the job, or the inability to pass a polygraph in a timely manner can cause you to lose your already existing job.

As far as I'm concerned failing a polygraph is no worse than an inconclusive one, because they are not admissible in court, yet they are often used for obtaining law enforcement or defense/intelligence related jobs.

Meg wrote on Apr 5^th, 2007 at 6:20pm:


I find it interesting that you say YOU can evoke an inconclusive result.  An inconclusive is not that hard to achieve if someone is truly innocent with regard to the relevant questions; the best way to get that inconclusive INSTEAD of passing it would be to mess around on the exam.  Now, if you had said you can easily PASS the polygraph by manipulating your physiology, that might be impressive, but only if you could tell us which RELEVANT questions you answered with a lie.  It's funny how anti-polygraph people jump on anyone's unfounded statement regarding his/her ability to pass a polygraph by using countermeasures as support for their own inexperienced beliefs or hopes.  More funny, actually, than when a polygrapher claims that the polygraph is more than 90% accurate.  I'm not impressed either way because I actually use the instrument and have more firsthand knowledge of its strengths and weaknesses than George or anyone else who has simply read about the polygraph or failed it.

LieBabyCryBaby wrote on Apr 14^th, 2007 at 1:32am:

I agree with your opinion that, as a polygraph examiner, you have more knowledge of the polygraph instrument itself.  However, it seems that you extend that opinion to imply that more extensive knowledge of the instrument gives you more extensive (and more credible) knowledge of the results of a polygraph exam.  I don’t think that is true.

As a polygraph examiner, you don’t receive as much clear feedback as the person who is taking the polygraph exam.  You measure various physiological responses and watch the person during the exam and then render an opinion that is X% likely to be accurate (depending on which source cited) as to whether the examinee was truthful or deceptive.

You cannot honestly say with complete certainty that every single person who ever “passed” your polygraph was being completely truthful on all their responses.  And you cannot say with complete certainly that every single person who ever “failed” their polygraph was not being truthful.

I’m sure in some cases you “catch” someone in a lie and when you interrogate them further, they confess to something.  Or you conclude at the end of an exam that the subject is lying and later some sort of conclusive physical evidence proves that they were.  Incidents like these are interpreted (correctly) as feedback which lends one to believe that the polygraph is useful and accurate.

However, it seems clear to me that feedback polygraph examiners receive is only going to be that type of “positive” feedback.  Negative feedback is automatically excluded as invalid feedback; when someone claims they told the truth after you concluded they were lying their protestations of innocence are naturally dismissed because you have already concluded they are liars.

Compare the feedback examiners receive to the feedback of someone like me.  During my polygraph exams I told the truth and was told by the examiner that I was lying.  I wasn’t rendering an X% likely to be accurate opinion on whether I was telling the truth – I know for a fact I was telling the truth.  And while telling the truth I was “failed” for being deceptive.  And this happened on my first three polygraph exams.

The experts in the workings of the polygraph are most likely polygraph examiners.  The experts in the results, or more precisely, the accuracy of the results, are the examinees, because only they know if they were telling the truth or being deceptive.

LBCB,

What fun is debate without an opposing position. Besides I do consider your opinions when you post them. I may choose to either let them be, or argue, but at least the issues get aired in due course.

Regards ...