TN_Cop wrote on Dec 27
th, 2004 at 10:56pm:
George-
The more you write and the more I read it seems like your that kid in the fourth grade who didn’t get his way on the basketball court and is crying foul to anyone who will listen. Before you bash something you admittedly know nothing about go and take the CVSA or polygraph course and become an examiner yourself. Then and only then will you have any basic knowledge to base your beliefs on.
I did not "admit" that I "don't know anything" about CVSA. You had only asked whether I was certified as a CVSA examiner. The fact that I'm not doesn't mean I don't know anything about CVSA.
Quote:The CVSA is based on the scientific fact that it can detect certain FM frequencies that are not heard by the human ear. The spoken voice that you hear when someone talks to you is AM frequencies and it is carried on FM frequencies. When someone is stressed the vocal cords and the voice box tightens and the FM frequencies are changed and the change isn’t detectable by the human ear. The CVSA does detect that change and it shows during the test.
The claim that CVSA can detect stress has yet to be proven through peer-reviewed scientific research (as does the claim that stress is diagnostic of deception).
Quote:Then a qualified examiner who knows how to read the patterns can interview and interrogate the tested based on the questions they showed stress on.
The patterns are easy enough to read. From the NITV website, in a
page whose title includes the claim that they are "Lie Detection Experts":
So, a pointy spike like an inverted "V" means that the person is telling the truth, and a flattened top, shaped more like an inverted "U," means the person is lying. (Almost as easy as reading a Magic 8-Ball.) And even if the qualified examiner has difficulty reading it, the computer can do it for him.
Quote:Like I have said many times before the CVSA is not a lie detector, it only detects stress reflected in certain patterns.
It's good that you acknowledge that the CVSA is not a lie detector, as NITV did in court. Yet as we have seen, on their website, NITV claim to be "lie detection experts" and purport to show how to tell a truthful response from a lie.
Quote:Obviously the government agencies that buy the machines are having tremendous success at what they do or they wouldn’t spend the money at all.
Not necessarily. Especially considering those making decisions to spend taxpayer money on the device are being misinformed by NITV about the device's capabilities.
Quote:I don’t seem to understand why you cant comprehend what the CVSA does, even my four year old understands and can pick out the stressed voice patterns on the test.
I understand psychophysiologist Dr. David T. Lykken's conclusions regarding voice stress analysis, which are based on a review of the research literature. He devotes a chapter of the 2nd edition of his seminal treatise,
A Tremor in the Blood: Uses and Abuses of the Lie Detector, (Plenum Trade, 1998) to voice stress analysis. He concludes:
Quote:
There is no scientifically credible evidence that the PSE [Psychological Stress Evaluator], the CVSA, the Mark 1000 VSA, the Hagoth, the Truth Phone, or any other currently available device can reliably measure differences in "stress" as reflected in the human voice. There is considerable evidence that these devices, used in connection with standard lie detection test interrogations, discriminate the deceptive from the truthful at about chance levels of accuracy; that is, the voice stress "lie test" has roughly zero validity. One business enterprise to learn this, to their cost, was the high-tech house of prostitution mentioned in an epigraph to this chapter. According to a 1979 story in the Chicago Sun Times, an undercover agent for the Cook County sheriff's vice squad was required to submit to a PSE lie test when he visited the house posing as a client. The test questions had to do with whether he was connected in any way with the police. To his surprise, the agent passed the test and was granted client privileges. The PSE was confiscated in the ensuing sheriff's raid but the news report does not reveal what finally became of it. Let us hope the Cook County sheriff is not using it to interrogate criminal suspects....
You also ask:
Quote:Have you ever even seen or been subjected to a CVSA examination?
Yes. A friend of mine who is a certified CVSA examiner (and understands full well that the "test" is completely bogus) administered a CVSA examination to me to familiarize me with the procedure.
I also had the opportunity to do a little test of my own. I simply said "no" into the microphone in a normal speaking voice, and not in response to any questions. I was quite relaxed. The situation was not stressful. But about 1/3 of the time, the CVSA said that I was being deceptive!
Quote:Seriously, go and take a CVSA course and become a certified examiner. It will take about 60 hours of your time and then you can bash rant and rave all you want and I will take your more seriously.
I think I'll pass. I already have a copy of the CVSA operator's manual, which I have read.
Quote:I know your responses before you even type them. Its the same every time and it gets old hearing the same old thing and the same old quotes. Try something original and get a thought of your own and then share it with the group.
Somehow, I suspect you did not know my responses before I typed them.
Quote:I’m sorry about your experiences with the FBI polygraph examination. I know its a bitch when one is falsely accused of doing or being something they are not. Just because you had a bad experience with the polygraph don’t bash the CVSA until you have some experience with the machine and what it can do.
Again, I think I've done my homework on the CVSA. Could you point me to any peer-reviewed research that supports the manufacturer's claims? For example, NITV marketing materials have claimed that the device has "an accuracy rate of 98%."
CVSA operators are taught to make similar claims about CVSA to those whom they "test." The following is straight out of the CVSA operator's manual:
Quote:CREDENTIALS: Tout your experience as a detective or as a CVSA operator. "I have been conducting CVSA exams for...years". (Brag!) My department selected me to attend the "NATIONAL INSTITUTE FOR TRUTH VERIFICATION"" I have specialized training in sex cases, homicide, child abuse, etc.
CVSA: (Pat or stroke the instrument whenever you mention it.)
(a) This is a foolproof way to begin to FOCUS their attention.
(b) The CVSA is the latest scientific equipment used in law enforcement.
(c) The CVSA is extremely accurate. (If you use percentages less that [sic] one hundred the subject may feel that he/she is in the percentage outside of the norm. That is, if you say 97%, he/she may feel they are in the remaining 3%.)
...
Where's the proof that CVSA has an accuracy rate on the order of 98%?
Pages: 
Failed a CVSA a few times (Read 12517 times)
