Twoblock wrote on Mar 19
th, 2008 at 4:32pm:
Sackett
I was told one time by a polygrapher that he much preferred the results of just the analog over the computer generated test because of the computer background noise.
Questions you may be able to answer:
Not knowing any more than I do about the operations of the poly (waiting on a wise-ass reply here), isn't the analog machine hooked directly to the computer? Doesn't the puter only reveal the results of the analog or does it enhance the analog device so as to reduce false positives. If so, how? How does answering these question reveal trade secrets? Hell, I'm not asking for a DACA produced computer program.
Twoblock,
the analog instrument refers to the mechanical/electrical instrument used in the past (like the one in "Meet the Parents"). Many "older" examiners prefer it to the computer based programs, usually due to fear/ignorance of the computer itself, lack of computer ability (i.e. comfortability) or not wanting to spend the money.
There is little difference in the tracings and there is nothing related to test technques (referring to your reducing of false positives statement or trade secrets), as it relates to the analog vs computerized process. They are simply different methods to record the same information.
The computerized polygraph has the ability to modify the tracings after the test for evaluation purposes. For example, if a tracing is too big or too small, it can be reduced or enhanced for evaluation purposes. Or, if a tracing goes off the screen during the exam, it can be returned, electronically after the test for evaluation reasons since there are no pen limits in the computer.
Once a computerized test has been recorded and saved to a file, it can not be altered, except for temporary evaluation purposes; however, the original is never altered. The analog produces paper charts and, for example, if the examinee eats a portion (actually saw that happen), it can not be reproduced, since the paper chart is the original.
I find interesting, your report of the examiner's comment that the computer background noise bothered him. I found, back in the day, the scratching of pens on the paper was more anoying than any computer noise...especially the cardio tracing, since when BP/volume increased, you could actually hear the pen speed up.
Thanks for the intelligent question. Hope that answered it sufficiently.
Sackett