Talk:Polygraph

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[edit] pov correction

I have removed "It is interesting to note that, so far, no scientific study has been published that offers convincing evidence of the validity of the polygraph test". What constitutes "convincing evidence" and "validity of the polygraph test" is really a matter of opinion. The very next paragraph says that the NAS found 57 scientifically sound studies that demonstrate that on average the polygraph is better than chance. Therefore, there really are 57 studies that convincingly show that the polygraph test is more valid than guessing. On some other interpretation it might not be, but Wikipedia is not a forum for private opinions. --151.203.14.68 22:03, 21 November 2006 (UTC)

[edit] One Million USA Dollars

The James Randi Educational Foundation will surrender US$1,000,000 to the first polygraph expert who steps forward and demonstrates the effectivness of polygraphs. Since polygraphs do not work --- they are pseudoscience devices --- his money is safe. Consider the fact that polygraph operators avoid his one million dollars, that is excellent evidence they know damn well the machine is utterly worthless in determining deception. Any polygraph operator out there who wants to be an instant millionaire with just a day or two of work may step forward and be tested by the JREF http://randi.org Desertphile January 08, 2006 10:46AM PST

I went to the JREF page noted, and found nothing about polygraphs. Whatever else a polygraph may or may not be, it is not "paranormal" - which is what the JREF challenge is all about.

[edit] Fruit Machine

Forgive me for being dense, but what does this article have to do with fruit machines? Koyaanis Qatsi 09:32 Feb 16, 2003 (UTC)

The fruit machine to detect homosexuality works quite similar to a polygraph. AxelBoldt 23:22 Feb 16, 2003 (UTC)

Sorry, I'd be a second-rate English major. Not too good with metaphor, and wouldn't know phallic symbolism from a pole in the ground. Koyaanis Qatsi

Nobody wants to banter? Ok, I'll do it:
"Nice Freudian slip."
"It's a camisole."
Thank you, thank you, you've been a great crowd. Koyaanis Qatsi

[edit] Used anywhere outside the USA?

Is there any single Western country outside of the US that allows its police and justice to use polygraphs? David.Monniaux 21:57, 3 Apr 2004 (UTC)

I know, as a barrister, that polygraphs are never used in Australia. They are regarded as laughable. I don't think any developed legal system outside the USA uses them. Unless someone objects I'm going to extend the paragraph about them not being used in Europe. Avalon 10:44, 20 October 2005 (UTC)
Yeah, most countries don't really care about polygraphs for justice. I mean on a certain level it works, but it can be deceived in quite a few ways. AllStarZ 02:02, 15 January 2006 (UTC)
To be more specific, is there at least one country in Latin America where polygraph examinations are admissible? If not in a criminal proceeding, how about in a civil proceeding, like determining whether you'll make a good employee for the government?


[edit] Take or not take

I came across this comment [1] and came over here to see whether there is a diffrent opinion offered in case you were asked to take a test. May be worth to address that in future. "In an interview, Ames was asked how he passed the polygraph test. His response was that when told he was to be polygraphed he asked his Soviet handlers what to do, and was quite surprised that their advice was simply to relax when being asked questions, which he did." Kind of remember reading this from a page of alleged USSR mole who was uncovered by Nixion i am not very sure though when some church minister brought the story to him.

[edit] Pseudoscience???

What is the justification for this article being included in the pseudoscience category? Factoid Killer 11:41, 5 December 2005 (UTC)

it IS psuedoscience.
Right... so it is pseudoscience because it is pseudoscience. hmmm Factoid Killer
I would say that since courts in several countries are accepting it as evidence (albeit evidence that isn't unequivocally trusted), "psuedoscience" might be slightly POV. On the other hand, the scientific studies and the scientific community seem to lean towards polygraphs being pseudoscience...? --Interiot 16:37, 6 May 2006 (UTC)

To answer the original question: the hypothesis is that a biometric test can establish, with meaningful accuracy, if a subject is lying. There is no evidence that this is true. While there might be weak correlation in some subjects between biometric indexes and the truthfulness of responses, this is far from enough to determine with any certainty if someone is lying. The system is prone to false positives (detecting lies when none exist) and false negatives (clearing subjects who *are* lying).

Its only use is as an interrogation technique (cf. good-cop, bad-cop) where credulous (and guilty) subjects might be convinced enough to confess. Against a prepared and determined subject it is worse than useless since it will generally clear him.

One convincing piece of evidence that this is pseudoscience is that it takes a substantial amount of time to "train" the operator - particularly in the interpretation of the data. This inability of the equipment to provide a clear yes/no answer and the dependency on the subjective view-point of the operator is particularly damning.--Oscar Bravo 19:16, 18 July 2006 (UTC)

Come now. It takes a substantial amount of time to train people in the interpretation of X-ray films and electrocardiograms too. Polygraphs may be bunk, but long training period does not demonstrate that. 72.75.103.211 18:51, 12 August 2006 (UTC)

Good point to compare polygraphs with ECGs - I was thinking initially in comparison to something like an alcohol breath analyser. This is a machine that answers the question "has the subject been drinking alcohol?" Many models simply flash a green, amber or red light because there is a very reliable correlation between the alcohol present in breath and the alcohol level in the bloodstream. Compared to a real scientific instrument like this, the polygraph is very weak.

Returning to the more difficult case of an ECG; it is true that the ECG is a lot less precise than the breathalyser and that a skilled operator is required to interpret its readings. However, where it differs from the polygraph is that certain heart defects do give rise to corresponding patterns in the readout, and that this is consistent over many subjects. In the case of the polygraph, the patterns that correspond to "lie" or "truth" have to be identified by comparison with patterns from control questions from the same subject. The margin for error is correspondingly large.

I am not disputing that some people might get sweaty palms when they tell a lie! But the incidence of error (positive and negative) is so large as to make the technique essentially worthless.--Oscar Bravo 13:36, 14 August 2006 (UTC)

I think its more important to establish if anyone notable calls it pseudoscience, or something that implies the same thing. But I personally think you're stretching the definition of pseudoscience. Seems to me a "real peudoscience"-based device should necessarily have a success-to-failure ratio of 50-50 in any decent study, because it's plain bogus. If lie detectors can even get 70% that's pretty interesting. 64.163.4.225 04:35, 6 September 2006 (UTC)

There are certainly more people than just me who call it pseudoscience (google "polygraph pseudoscience" returns >800 hits). Whether any of them are notable is a matter of opinion. Certainly, some skeptics think it's pseudoscience (http://www.skeptics.org.uk/article.php?dir=articles&article=polygraph_or_lie_detector.php) but then, you'd expect them to say that. With regards to how "accurate" it is - the answer would be "very hard to tell" (the link above reports claims of between 50% and 99%). It is difficult to construct an experiment that would reliably measure its efficacy. For example, there are cases where a guilty subject confesses during a session. These are claimed as a positive hit by polygraph proponents. However, the confession could just be motivated by the fear that polygraph might work and the desire to lessen punishment by co-operating (the prisoner's dilemma). How to subtract out this "placebo effect" is the big problem in any experiment.

The principle of the polygraph rests on the conflation of two hypotheses:

  • Lying makes you anxious
  • Anxiety can be quantitatively measured

Neither of these can be regarded as hard facts that are true all the time, everywhere. More likely:

  • Lying often makes some people a bit anxious
  • Anxiety can sometimes be correlated with things that can be inaccurately measured

Woolly x wooly = extremely fluffy :-) --Oscar Bravo 06:59, 6 September 2006 (UTC)

The following people and organizations hold advanced degrees in relevant fields and find the accuracy of the polygraph questionable:
Charles Honts, Ph. D., Boise State University a professor of psychology. His webpage can be accessed here. It contains a wealth of information regarding the use of the polygraph as a screening tool.
American Psychological Association states “Most psychologists agree that there is little evidence that polygraph tests can accurately detect lies.” The link is available here.
David Lykken, Ph. D., a professor of psychology at the University of Minnesota. His Curriculum Vitae is here, if you examine it closely you find that he was a consultant for the Department of Defense Polygraph Institute. His opinion on the polygraph is available here.
A more interesting question would be to find a relevant expert outside the polygraph community that believes polygraphs are not pseudo-science.
Max The Dog 21:19, 6 September 2006 (UTC)

It is clearly not "hard science". But then neither is psychology. Can you make a test for depression or schizophrenia that are 100% accurate and can't be faked?

According to what I've read, the whole process is set up to make a person get nervous when they lie, then the machine measures the nervousness level. It may not be mind-reading but it may well be a process which can detect lying... sometimes anyway. Shake out some percentage of criminals/spies on whom it works, and deal with the rest the old-fashioned way. It certainly makes a lot more sense than, say, interpreting their astrological sign. The question would be is it more accurate than that. Lykken's claim that "Polygraphs are a little more accurate than flipping a coin" sounds like a concession that they are real science, just not accurate enough to rely on. Well that's an entirely different argument that the hyperbole of many of the critics.

The criticism from the American Psychological Association and the argument that there have been no successful studies are definately damning though. I can think of a way to make a thorough scientific study, but to give that element of realism to produce nervousness it would involve shocking people when caught lying. 64.163.4.225 00:49, 7 September 2006 (UTC)

Psychologists performing schizophrenia examinations also acknowledge the limits of their ability. Let me ask this question: After a pap smear would we go out and perform a hysterectomy? Certain polygraph tests have a degree of utility. Even critics acknowledge that polygraphs regarding a specific incident have a statistically significant degree of accuracy. John Furedy a critic of the polygraph based at the University of Toronto places some faith in the Guilty Knowledge Polygraph.
Even the American Polygraph Association recently reversed itself and decided “The decision to hire, or not to hire an applicant, should never be based solely on the results of the polygraph examination.” [2] This is a stark contrast to claims of accuracy that exceeded 95%.
The majority of polygraphs performed today are done for screening purposes with government agencies. The polygraph exclusively determines if an applicant is hired. They also are used as the exclusive basis to grant a security clearence. No further investigation is performed. These are not the specific incident polygraphs that Lykken is discussing. The zealous reliance on polygraph exhibited by intelligence & law enforcement agencies for mass screening purposes approaches a level of pseudo-science, that expects far more utility & accuracy than a polygraph is capable of.
However, Wikipedia operates on a consensus basis and your input is appreciated.
Regards,
Max The Dog 02:44, 7 September 2006 (UTC)

A critical test of whether something is a pseudoscience or not is to ask, "Has it developed over time?". For example, Shockley's original transistor was the size of a shoebox. Now, we fit a zillion of them onto a pin-head. So semiconductor physics is a science. On the other hand, astrology still relies on the movements of the 200 naked-eye objects that were known to Ptolemy and ignores quasars, pulsars, precession of the Earth's axis and anything else that has been discovered since the Renaissance - hence it's a pseudoscience.

So what about polygraphs? If they were 55% accurate in 1950, you'd expect them to be a darn-sight better nowadays what with all the discoveries they'd have made by now, wouldn't you? But they ain't... OK, they might use a lap-top instead of a plotter to display all the wavy lines, but they are still very far from accurate. --Oscar Bravo 10:45, 8 September 2006 (UTC)

When I first saw this page I was shocked to learn the gov't was putting so much stock in something that was complete bullshit. Then I read further and I'm annoyed to discover I have been manipulated by criticism based on hyperbole and logical fallacies. And those (few but loud) "anti-polygraph" pages read like a bunch of government-bashing agitprop. The accuracy is whatever it is. You shouldn't round it up and claim it's perfect any more than you should round it down and claim it's zero. I really don't think the manner in which "The Man" reacts (or overreacts) to results is relevant except as a social or political topic.
I had one of those multi-project science kits as a kid which had a lie detector project in it. You hold a couple wires and it measures your skin resistance, though I could never get it to work. In fact a google search for science kit and "lie detector" has about 50k hits. Should we accuse them of selling "pseudoscience kits"?
By the way, here's some talk about new technologies: [3] [4].64.163.4.225


The accuracy is whatever it is. I think you've hit the nail on the head - nobody knows what the accuracy is! This is because there is no way to measure definatively its performance. There is no way to design an experiment that allows you to measure how well a polygraph works because, in the real world, there is no way to know if the subject is lying. What can be shown is that extremely honest people often become excited and uncomfortable by the mere act of interrgation and so fail (false positives) while skilled liars can adopt countermeasures and pass (false negatives - no spies have ever been caught by a polygraph).

As Max points out, it is rather the reliance on polygraph tests by government departments that should know better, that is pseudoscience. By the same token, the idea that magnets affect healing isn't pseudoscience (it's just wrong), but strapping a magnet onto your stiff knee-joint, is. --Oscar Bravo 12:47, 11 September 2006 (UTC)

Again, I completely disagree that politics has any bearing on the categorization of something as pseudoscience or not. In fact I'd say such lines of argument are bad for science in general. It's why nobody ever believes what anyone says about global warming or whether missile defense is possible.
As for accuracy, we don't need to pin down the exact level. We only need know it is more accurate than a random guess. Consider it from a statistical perspective. If you can construct a test where the output is correlated with the variable you tried to measure, then that is science. It does not need to be a perfect correlation. In fact it never will be due to noise and other errors. But perfection or near perfection is not remotely a requirement to be called science. Especially when dealing with human subjects. Some (such as Tom Cruise) call psychiatry a pseudoscience. I'm sure he has all kind of reasons, and psychiatry is littered with missed diagnoses and flawed methods. Is that all it takes? And yes I would say magnetic healing is pseudoscience. Science is not devices it is theories. If a theory can't be validated by experiment it isn't scientific.
I'm removing the category. A handful of equivacal statements about accuracy does not rate categorizing the method with the likes of divining rods and astrology. 64.163.4.225 22:51, 11 September 2006 (UTC)
By the way we still have no references of notable sources calling it pseudoscience, much less a significant enough number of them to not rate as undue weight to an extreme minority view. And I don't consider the above sources such as the NAS to be making that claim. The references I've looked at basically say it is effective in law enforcement but not in screening. Fine don't use it for screening. That doesn't mean throw it out with the trash. 64.163.4.225 00:12, 12 September 2006 (UTC)

Who mentioned politics? I have no political agenda. Unfortunately, we seem to be drifting into that area of debate where we each fail to understand each other's argument. Let's try to get back on an even keel:

Your point about Tom Cruise and psychiatry is a good one - I think that the difference is that psychiatrists are aware of and publish the margin of error in their diagnoses (rather like any quantitive scientist will publish a result with plus/minus error-bars). The pseudoscience in the polygraph is not in the machine itself (as others have pointed out, it does measure physical things, like skin conductivity), but rather in the belief that it provides a definitive answer to the question "is this person lying?".

Regarding "notable references" - what's wrong with the list compiled by Max the Dog above?

The problem is that these machines are not used for epidemiological, Bayes theorem studies of populations, they are used to decide the future of real people in peril of incarceration or unemployment. In such critical cases, they have to be foolproof - but they ain't. --Oscar Bravo 13:24, 12 September 2006 (UTC) (BTW, you keep forgetting to sign your posts).

I don't mean politics as necessarily the federal government (though there is that aspect in some of the criticism, for example on antipolygrah.org). I mean it as the attempt to criticize or control the interactions of groups of people. For example the agenda that their use to "to decide the future of real people in peril of incarceration or unemployment" should be stopped.
However besides that, I think we can agree that:
1. Polygraphs are pretty widely variant in performance, seem like more of an art than a science. And in particular have a high false positive rate which likely makes them ineffective for screening very rare people like spies: If .01% of the population is a spy and the false positive rate is 10%, then your false positives will outnumber your true positives by a factor of 1000, and you screw over a whole lot of innocent people if you misuse that info.
2. Polygraphs are probable beatable with training/practice and perhaps just ineffective against a significant segment of the population in general. Making it further unlikely that an intelligent and motivated person like a spy would fail.
3. "Polygraph people" appear to greatly exaderate their success rate since it would obviously be in their best interest (given the above two flaws), both in the testing room, and just getting more business. In fact the polygraph industry as a whole seems to either not bother or actively avoid performing scientific studies for the most part--after all their "propaganda" seems to work for them just fine.
Now where we disagree - If something has the above flaws it is pseudoscience: no. Bad science, or technicians masquerading as scientists, does not in itself rate condemnation as pseudoscience, though much of it could be called "junk science". Those flaws certainly don't help, but are not sufficient to say the science is in fact false. There is a very important counter argument, which Max the Dog's critics also allude to, and it is the successes which demonstrate the device is definately more than just a bluff. The have been several promising studies according to the FAS [5]. In law enforcement the false positive rate is not so bad relative to the guilty rate, and there the subjects are probably not as often of the level of intelligence to beat the test. Not to mention some of us have learned with our own science kits the actual reasonableness of the scientific basis for the devices. If there's something of scientific value there being exploited (however successfully), which is actually measurable experimentally, then we shouldn't throw the baby out with the bathwater. I have no problem with the polemic tone of the article. We can of course even link the term pseudoscience in the text with a source, but I don't agree it fits the category.
Also, according to all the fuss over Chiropractic, the wikipedia category guidelines for inclusion are pretty strict. For something to be included it should be an good example of the category, not a weak one. 64.163.4.225 22:41, 12 September 2006 (UTC)

Good response, 64.163.4.225 - I think we're getting somewhere. In case you're in any doubt, I have never argued that the machines themselves are pseudoscientific (cf. magnetic water cleansers). I accept that they really do measure physical attributes like skin conductivity, heart-rate etc. I also accept that those attributes vary in many people as a result of anxiety. I even accept that most people get a bit anxious when they tell a lie. Putting it all together, I'm sure that if you had a sample of a fifty liars and fifty truth-tellers, the polygraph would have a significantly better than chance probabilty of sorting them (eg, it might assign 40 liars and 8 truth-tellers to the "Liar" group and 52 truth-tellers and 10 liars to the "Truth" group). So far, it's science.

The trouble is when you apply this science to a particular subject; we hook the butler up and ask him "Did you do it?". If he says "no", but the machine shows a "lie", is he guilty? I'm not a statistician, but if you apply the data in my imaginary experiment to the appropriate statistical method (Bayesian?) you'd find that we could only answer yes or no within a limited confidence-level. The pseudoscience comes in when the result of the machine is treated as definitive (in the refs above, there is a story about a suspect who was offered the choice - take a polygraph; if you pass, you go free, if you fail, you agree it's an admission of guilt. He failed and spent years in jail before being cleared on new evidence).

Maybe we should say "belief in the definitive efficacy of the polygraph is pseudoscience". --Oscar Bravo 06:55, 13 September 2006 (UTC)

I have no problem with that statement in the article. But to minimize the revert warring that has been with this page since the beginning, it would be best if stated as part of a sourced statement. soandso calls the polygraph pseudoscience. Or if necessary use weasel-words: Many critics have lambasted the device as more pseudoscience or junk science than actual science. I just don't think it's fair to use the "category" on the page because it implies too broad a claim to some of us readers. Plus we obviously don't want to claim every single agency and operator that uses the polygraph commits those mistakes in interpretation. 64.163.4.225 05:06, 15 September 2006 (UTC)

"Bad science, or technicians masquerading as scientists, does not in itself rate condemnation as pseudoscience", you pretty much quoted the Merriam-Webster definition of pseudoscience while trying to argue that it is not a pseudoscience.76.18.100.128 23:57, 27 September 2006 (UTC)

I'm sure if anything it's the definition of junk science. just like I stated in context back there... 64.163.4.225 00:31, 30 September 2006 (UTC)

[edit] MRI

I just heard about how they are developing a MRI-based polygraph that's more accurate. Anyone know anything more about it?--PullUpYourSocks 13:53, 17 January 2006 (UTC)

[edit] Opening Paragraph

"A polygraph or lie detector is a device which supposedly measures and records several physiological variables..."

I'm editing this sentence. It doesn't "supposedly" measure these variables, it does measure them. The supposed part comes in as to whether or not it can detect lies. 82.4.43.19 23:29, 26 February 2006 (UTC)

[edit] It's not a "lie detector," shouldn't be referred to as one

A polygraph is not called a "lie detector," that is an informal street name (similar to calling Sodium Pentothal "truth serum") that is inaccurate and somewhat dangerous. If everyone matter-of-factly call polygraph tests "lie detectors" then people will actually believe that they are reliable in judging if someone is lying. I think any reference in this article, since it is supposed to be an encyclopedia, to "lie detectors" should come with a clarification such as "they are commonly referred to as 'lie detectors'" I don't want to see a polygraph actually called a lie detector, because that's an incorrect name.

I think the fact that noted skeptic James Randi (See above) has included Polygraphs in his million dollar challenge should be included in the article, as should the fact that no polygraph expert has taken this challlenge. Surely, if polygraphs worked as a detector of lies so reliably, someone would have taken Randi up on his challenge and easily collected the million dollars. No one has, because if someone were to so publicly fail with a polygraph, everyone might realize that they are a sham pseudoscience. --—The preceding unsigned comment was added by 199.2.242.61 (talk • contribs).

The encyclopedia entry shouldn't necessarily promote the use of the term "lie detector", but it should at least recognize that it's colloquially refered to as that, especially in the US. (I count 4 million hits for "polygraph" and 2 million for "lie detector").
Or, maybe do like they did with truth drug... note in a new article lie detector that it's a semi-unatainable technological marvel that people are searching for, and that a polygraph test is but one of the ways to attempt to achieve that.
--Interiot 16:43, 11 April 2006 (UTC)
_ _ The article should promote neither the accurate nor the common term. We generally use the common term, regardless of any promotional effect it has. In this case a more sensitive test is
680 of about 1,240,000 for -"lie detector" polygraph
803 of about 801,000 for "lie detector" -polygraph
which suggest (in thousands) 1200*70% = 840 vs 800*80% = 640, or a 57/43 split between authors (as opposed to site-copiers) who think calling it "polygraph" means not needing to mention "lie detector", vs. vice-versa.
_ _ (BTW, "polygraph" in the Merriam-Webster OnLine Collegiate Dictionary implies it is careless usage to say "polygraph" in the sense under discussion w/o specifying the purpose of the multi-variable recording device in question, and the "lie detector" entry sees no reason to mention "polygraph" -- i.e., "polygraph" is an inaccurate term when you mean the subject of this article, polygraphs with specific integrated biometric sensors. But i digress.)
_ _ It should also be kept in mind that article titles are essentially nothing but effective navigational devices, and are an ineffective tool for informing users about inaccurate terminology: even the lead sentence, let alone an extended section (linked from the lead 'graph), is a far more powerful means for clarifying terminological problems.
_ _ IMO, the bottom line is that even if "Polygraph" as the title presented no accuracy issue, the inaccuracy of "Lie detector" as the title is a minor issue, but using Lie detector as a rdr to an article Polygraph, as at present, is confusing (bad for navigation) bcz of the ToP Dab it requires, which is inadequate in spite of being a two-way Dab: "polygraph" means
  1. stress-detecting polygraph,
  2. other recording devices,
  3. the human-powered pantograph that Jefferson used analogously with carbon paper, and
  4. Autopen (a probable trademark for a probably electrically operated device for simulating the hand-writing of signatures, only vaguely related to the Jefferson era devices; probably only the careless or clueless either call Autopen a "polygraph" or call the hand-driven lever assembly an "autopen". Whoops, the shortcomings of Autopen are off-topic here!)
I'll thus propose language with a single-arm ToP-Dab, in light of Rdr'g Polygraph to Lie detector, to Polygraph (disambiguation), and clarity in the lead sentence about the implicit false claim, e.g. "measure physiological variables commonly present under psychological stress" and something about no one claiming it's reliable without a skilled operator, and lacking conclusive scientific evidence for effectiveness.
--Jerzy•t 20:51, 14 December 2006 (UTC)
Two minor points:
  1. Altho it's off-topic here, note i intentionally avoid the familiar "... redirects here" wording; i will advocate a WP-wide change, at least on my talk page, if asked.
  2. The ToP Dab "For other uses, see Lie detector test (disambiguation)" is inappropriate, since that Dab page lks to only one other page, which provides no information on the song "Lie Detector Test" beyond its length, the album it appears on, and the band recording it. Until there is more to say about the song, users would be better served by dropping that portion of the ToP Dab and adding a bullet point giving that info (and lk'g the album title) within the "Popular culture" section of this talk page's article. (Lie detector test (disambiguation) should then be deleted.)
Here's what i have in mind:
"Polygraph" is an alternate title for this page about the machine for forensic investigations; for various machines with other purposes, see Polygraph (disambiguation).
A lie detector or (more formally and accurately) polygraph machine is a measuring mechanism sometimes used while interrogating a "subject" who might have a motivation to intentionally make false statements. The name "polygraph" (from the Greek for "multiple" and for "write") refers to its function of recording the variations in a handful of physiological quantities that, for many subjects, are influenced by the subject's current degree of psychological stress. At best it detects not lies, but physical quantities that may be influenced by various factors about the subject: their awareness of speaking truly or falsely, their anxiety about other matters, or their intentional efforts to influence those quantities. Further, the operator of the machine has the responsibility of making judgments, based on special training, about the implications of those quantities. The effectiveness of the machines, or lack of it, is a matter of controversy.
--Jerzy•t 06:10, 15 December 2006 (UTC)

[edit] Shouldn't there be a link to brain fingerprinting?

Shouldn't there be a link in the article on polygraphs to the article on brain fingerprinting? It seems to me the two devices are related.24.92.48.99 06:30, 15 April 2006 (UTC)Bennett Turk

[edit] Colander + Xerox

The discussion of the "bogus pipeline" should not be in this article. The article is called "Polygraph". Either give "bogus pipeline" its own article or discuss it at Lie. --Mathew5000 21:27, 4 June 2006 (UTC)

I Agree Factoid Killer 22:11, 4 June 2006 (UTC)

[edit] 2003 NAS Report

Analyst 33, please stop deleting the section regarding the NAS report to congress regarding the polygraph. If you have a suggestion to improve the section please discuss it here. Max The Dog 02:43, 6 September 2006 (UTC)

Also, regarding the accuracy of a polygraph the statement that they are 90%+ accurate regarding specific issue polygraphs is misleading. This statement fails to take into account inconclusive results. Finally, the NAS found the median accuracy of a specific issue polygraph to be around 88% and varied from 70%-95%. Max The Dog 03:02, 6 September 2006 (UTC)

[edit] Weaselly

Someone feel like cleaning up all the weasel words in here, and getting some citations? Mikepurvis 13:13, 29 September 2006 (UTC)

[edit] Aldrich Ames

This article says that Aldrich Ames passed two polygraphs while spying for the Soviet Union, but that article says that he failed three times and explained his way out of it. Not only are the numbers inconsistent, the results are opposite! Sewebster 08:00, 1 November 2006 (UTC)


[edit] William Moulton Marston?

I had always thought that William Moulton Marston invented the polygraph as well as Wonder Woman - should his involvement in creating the "systolic blood-pressure test used to detect deception" be mentioned? j-beda 11:39, 1 November 2006 (UTC)

He was the first to suggest the use of systolic blood pressure as a lie detection method, but since it had only one input it could not be called a "polygraph". Nonetheless the article was extremely misleading as it was, and I have fixed. Maury 12:44, 2 November 2006 (UTC)

[edit] A few more issues

  1. The significance of the polygraph extends beyond whatever efficacy it has in exposing lies told while on the machine: fear of exposure by the machine can influence a guilty subject's strategy under interrogation, and a fictional film or TV show involved detectives Xeroxing the suspect's hand and claiming this "test" exposed the lie, inducing the suspect to confess in detail.
  2. 4 quantities are listed, but 5 needles appear in the photo -- why?
  3. The 4 quoted are really (1) chest circumference, which reflects depth of inspiration or exhalation (2) skin conductance, which reflects perspiration rate, and (3) blood pressure, of which the peak and trough values reveal systolic and diastolic pressure and the time between peaks or troughs show the heart rate. (But it may be that separate sensors (on arm and finger?) are useful for measuring the timing and the height-and-depth aspects.) What's the 5th variable, and maybe the 4th?

--Jerzy•t 06:41, 15 December 2006 (UTC)

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