What does it mean to "Pass" or "Fail" a polygraph exam?

Started by nopolycop, Oct 30, 2007, 11:17 AM

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Sergeant1107

Quote from: Barry_C on Nov 04, 2007, 04:44 PM"I feel...."  "I believe...." "I am of the opinion...."  "I divined...." Who cares what you or I believe when there's scientific evidence to consider?  I've given you the math.  Did I err in my calculations?  If not, I've demonstrated how a valid test (as long as it's better than chance), is more fair in the end.  The only debate is now polygraph accuracy.

Sarge,

You took a screening exam.  They are not as reliable as a single-issue test, which, I think, we all agree.  If you took one and were a victim of the error rate, then taking the same test again and again is only likely to repeat the same "error."  Did the fourth examiner do something different, or don't you recall?

I have tested people using a multi-issue screening exam, and yes, they have significant reactions to some questions.  Follow-up testing has cleared them, but if I had just run the same screening exam, I'd likely have ended up with the same results.  (I've never crunched the numbers, but most of those with SRs on a screening exam have later admitted to failing to disclose something.  I'd venture a guess that it's closer to 100% than it is 90% who fall into that category, which is another reason agencies are willing to play the odds.)

What I believe is based on my own experiences and the reading and research I have done.  What you believe is based on your own experiences and the reading and research you have done.

I've cited evidence too, but you don't believe the NAS research study was valid.  You are free to believe whatever you wish.  Kindly allow me the same courtesy.

I disagree with your assertion that you have demonstrated how any test that is better than chance is "more fair" in the end.  You have not demonstrated any such thing.  How is it fair to all the people who tell the truth and are still disqualified?  How is it fair to the agency that hires a deceptive person who passed the polygraph?  How do you know for certain how many truthful people will fail, and how many deceptive people will pass?  The plain truth is that you don't know, but that you believe both numbers to be small.  

As I have mentioned before, in the vast majority of pre-employment polygraphs (whenever there is no disqualifying admission made by the applicant, and/or whenever there is no physical evidence to corroborate the DI or NDI) the examiner cannot possibly know for certain if their conclusion of truth or deception was correct.  They can render an opinion based on their training and experience, and in some cases they will be correct.  In some cases they will be incorrect.  The only person who knows for certain is the subject.

Polygraph examiners can cite specific studies that support their beliefs, and can claim that any study that does not is invalid.  People who do not believe in the validity of the polygraph can do the same.  If I can cite a research study by the National Academy of Sciences, whose members have been awarded more than 170 Nobel Prizes, and you can simply dismiss it because you do not agree with its conclusions, then clearly you are not going to accept any study that does not support the polygraph.  That, of course, is your prerogative.

If neither side is going to accept any scientific evidence unless it supports that side's opinion, then we are left with nothing more than our personal experiences and anecdotal evidence.  In such a circumstance, the only "expert" with regards to the results of a polygraph is the subject, because only the subject knows for certain if they were being truthful or deceptive.  The examiner can render their opinion on the accuracy of any single polygraph exam, but only the subject can definitively state if the DI or NDI result was accurate.

In my experience, I told the truth on four polygraph exams and in three of those exams neither the instrument nor its operator was able to determine that.  Not only was the examiner unable to determine I was telling the truth, but they incorrectly concluded I was lying.  I don't see how I could have been a victim of the "error rate" when I was judged to be deceptive on three separate areas.  If I had some sort of issue about drugs, perhaps it would make sense if I kept failing because of drug-related questions.  But I failed for three different reasons, and never for the same reason twice.  I don't see how any reasonable person could go through that experience and not come to the conclusion that the polygraph is incapable of detecting deception.  I think it would be completely unreasonable for someone to go through an experience like mine and conclude that the polygraph didn't detect anything for them, but that it probably detects truth or deception with a high degree of accuracy for everyone else in every other situation.

Your post seems to suggest that it would not be unheard of for a police applicant to be a victim of the "error rate".  What makes you think that a large percentage of police applicants are not victims of the same error rate?  Other than the testimony of the applicants themselves, how would you ever be able to determine the actual percentages that are victims of the error rate?  

From your post, the "error rate" certainly does not seem to be a source of concern for you.  But, inexplicably, at the same time you feel comfortable endorsing the pre-employment polygraph screening exam as being "more fair" in the end than not conducting a pre-employment polygraph screening exam.  I don't see how you can do that.  You are willing to acknowledge the "error rate" but you have no way of definitively knowing what that rate is.  I realize you believe the error rate is low, but you don't really know that, so how can you believe that conducting pre-employment polygraph screening is "more fair" than not conducting pre-employment polygraph screening?
Lorsque vous utilisez un argumentum ad hominem, tout le monde sait que vous êtes intellectuellement faillite.

nopolycop

Okay, back to the original question.  It is the polygrapher's opinion as to whether or not an individual is lying or telling the truth, correct?  If the polygrapher feels the individual is lying, he fails.  If he believes the individual is using counter measures, he fails.  If the polygrapher does not detect any counter measures, and believes the individual is being truthful, he passes correct?

So, where does that leave the inconclusives?  If a person has to "Pass" a poly to get a job, but the polygrapher says he cannot give an opinion, does that mean a "Pass?"
"Although the degree of reliability of polygraph evidence may depend upon a variety of identifiable factors, there is simply no way to know in a particular case whether a polygraph examiner's Conclusion is accurate, because certain doubts and uncertainties plague even the best polygraph exams."  (Justice Clarence Thomas writing in United States v. Scheffer, 523 U.S. 303, 118 S.Ct. 1261, 140 L.Ed.2d 413, 1998.)

Barry_C

QuoteWhat you believe is based on your own experiences and the reading and research you have done.

One, you don't know that, and two, the two don't always jibe, which is why I must be data driven.

QuoteI've cited evidence too, but you don't believe the NAS research study was valid.  You are free to believe whatever you wish.  Kindly allow me the same courtesy.

I never said the NAS report wasn't valid.  It's really not a new "study."  It was more a of meta-analysis of what was out there already.  They pointed out that research in screening situations was lacking, and I agree.  They also stated some opinions that have since turned out to be wrong, so to blindly accept it in totality is an error.

QuoteI disagree with your assertion that you have demonstrated how any test that is better than chance is "more fair" in the end.  You have not demonstrated any such thing.

You're letting emotions get in the way of reason.  What I posted is a very basic statistical analysis, and the premise is well-accepted in the scientific community.  To argue otherwise is to deny reality.  You are free, however, to reject the accuracy rates, which I stated, but the rest is well-settled.

QuoteHow is it fair to all the people who tell the truth and are still disqualified?  How is it fair to the agency that hires a deceptive person who passed the polygraph?

It isn't fair, which is why we use polygraph as it, in the end, makes the playing field more level.

QuoteAs I have mentioned before, in the vast majority of pre-employment polygraphs (whenever there is no disqualifying admission made by the applicant, and/or whenever there is no physical evidence to corroborate the DI or NDI) the examiner cannot possibly know for certain if their conclusion of truth or deception was correct.

That's true of most everything in life.

QuotePolygraph examiners can cite specific studies that support their beliefs, and can claim that any study that does not is invalid.

Yes they can, but most don't.  With enough studies there are always going to be those (just by chance) that don't support polygraph (or anything subjected to scientific experimentation) as expected.  That's why we look at multiple tests, and that is why the NAS had a problem with screening exams.  We need more data.  What we have shows it works, but there are unanswered questions.  Why don't you consider taking part in a study?

QuoteIf neither side is going to accept any scientific evidence unless it supports that side's opinion, then we are left with nothing more than our personal experiences and anecdotal evidence.  In such a circumstance, the only "expert" with regards to the results of a polygraph is the subject, because only the subject knows for certain if they were being truthful or deceptive.  The examiner can render their opinion on the accuracy of any single polygraph exam, but only the subject can definitively state if the DI or NDI result was accurate.

And your point is?

QuoteIn my experience, I told the truth on four polygraph exams and in three of those exams neither the instrument nor its operator was able to determine that.  Not only was the examiner unable to determine I was telling the truth, but they incorrectly concluded I was lying.  I don't see how I could have been a victim of the "error rate" when I was judged to be deceptive on three separate areas.  If I had some sort of issue about drugs, perhaps it would make sense if I kept failing because of drug-related questions.  But I failed for three different reasons, and never for the same reason twice.  I don't see how any reasonable person could go through that experience and not come to the conclusion that the polygraph is incapable of detecting deception.  I think it would be completely unreasonable for someone to go through an experience like mine and conclude that the polygraph didn't detect anything for them, but that it probably detects truth or deception with a high degree of accuracy for everyone else in every other situation.

Your post seems to suggest that it would not be unheard of for a police applicant to be a victim of the "error rate".  What makes you think that a large percentage of police applicants are not victims of the same error rate?  Other than the testimony of the applicants themselves, how would you ever be able to determine the actual percentages that are victims of the error rate?  

From your post, the "error rate" certainly does not seem to be a source of concern for you.  But, inexplicably, at the same time you feel comfortable endorsing the pre-employment polygraph screening exam as being "more fair" in the end than not conducting a pre-employment polygraph screening exam.  I don't see how you can do that.  You are willing to acknowledge the "error rate" but you have no way of definitively knowing what that rate is.  I realize you believe the error rate is low, but you don't really know that, so how can you believe that conducting pre-employment polygraph screening is "more fair" than not conducting pre-employment polygraph screening?

I am very concerned about the error rate, but again, like you, that's a philosophical position I hold.  I don't think you understood what I meant by "error" here, so be careful about drawing conclusions.   You need to read my post again, and try to following the numbers.  It's just math.  Your other issues are just that: other issues.  It's incorrect to merge the two.



Hunter

the polygraph examination is a valuable investigative aid as used in conjunction with, but not as a substitute for, a thorough investigation.

Would this type policy help you be more accepting of the use of polygraph?

Twoblock

Hunter

I can only speak for myself, but I believe more people would accept the polygraph if it was used as an investigative aid and not the sole deciding factor for LEO applicants. However, I have continually read here that it is the sole deciding factor (because of not enough background investigators, costs etc.,) and if one fails a Federal Employment poly then said applicant is blackballed in all other LEO applicatons. This is wrong. I have read horrow stories here about applicants being verbally (cursed) and physically (BP cuff being so tight that the fingers turned blue which is unnecessary to register continuous BP changes) abused by polygraphers. I think we will all be against a one person one machine jury.

Even in a criminal situation I think the polygraph would be more acceptable if the it was used only as anunbiased investigative aid and the polygrapher was not able to testify as to guilt or innocence or relate this to the investigator. Tell the investigator only the subject showed physiological changes in certain areas e.g. time and place. This would save the investigator time and steps. The poly should never be used solely to convict.

Hunter

the polygraph examination is a valuable investigative aid as used in conjunction with, but not as a substitute for, a thorough investigation.  




"I can only speak for myself, but I believe more people would accept the polygraph if it was used as an investigative aid and not the sole deciding factor for LEO applicants. "

What was quoted is the model policy advocated by the American Polygraph Association for all agencies, including private examiners.  It is in fact part of my departments policy and I am sure other departments have adopted it also.  I do expect it to become the standard in polygraph. Polygraph examiners don't hold themselves out to be perfect in most cases.  We have a few, but very few that would say polygraph is 100%.  That is why I don't understand all the posts on this board that label Polygraph Examiners as bad or corrupt persons that cannot admit to making a mistake.  We are humans and our profession advocates the quoted policy.  Only a few are opposed.  So lets take a break and look a little closer at polygraph and what the Professional Associations advocate, rather than pick all examiners apart for a minority of examiners mistaken ideas.  Polygraph is the best we have now, and it will get better, I'm sure as we continue to research and change methodology in our chosen profession.  Advancements are made almost daily in all fields of psychology, physiology, medical and other fields, we are no different.  

George W. Maschke

#36
Quote from: Hunter on Nov 05, 2007, 11:35 PMthe polygraph examination is a valuable investigative aid as used in conjunction with, but not as a substitute for, a thorough investigation.  




"I can only speak for myself, but I believe more people would accept the polygraph if it was used as an investigative aid and not the sole deciding factor for LEO applicants. "

What was quoted is the model policy advocated by the American Polygraph Association for all agencies, including private examiners.  It is in fact part of my departments policy and I am sure other departments have adopted it also.  I do expect it to become the standard in polygraph. Polygraph examiners don't hold themselves out to be perfect in most cases.  We have a few, but very few that would say polygraph is 100%.  That is why I don't understand all the posts on this board that label Polygraph Examiners as bad or corrupt persons that cannot admit to making a mistake.  We are humans and our profession advocates the quoted policy.  Only a few are opposed.  So lets take a break and look a little closer at polygraph and what the Professional Associations advocate, rather than pick all examiners apart for a minority of examiners mistaken ideas.

Hunter,

With regard to law enforcement pre-employment polygraph screening, the American Polygraph Association's model policy goes even further than what you have quoted, stating at para. 3.12.1.3, "The decision to hire, or not to hire an applicant, should never be based solely on the results of the polygraph examination." (For earlier discussion, see American Polygraph Association Model Policy.)

Unfortunately many, if not most, law enforcement agencies with pre-employment polygraph screening programs (including all federal ones) will disqualify an applicant based on a failed polygraph alone. It would be nice to see the APA take a more proactive stance against such practices.

QuotePolygraph is the best we have now, and it will get better, I'm sure as we continue to research and change methodology in our chosen profession.

The National Academy of Sciences found polygraph screening to be completely invalid and that further investments in polygraph research are likely to produce at best only modest improvement, concluding that "[polygraph testing's] accuracy in distinguishing actual or potential security violators from innocent test takers is insufficient to justify reliance on its use in employee security screening in federal agencies."

QuoteAdvancements are made almost daily in all fields of psychology, physiology, medical and other fields, we are no different.  

Yes you are. The NAS found (at p. 213 of its report):

QuoteResearch Progress Research on the polygraph has not progressed over time in the manner of a typical scientific field. It has not accumulated knowledge or strengthened its scientific underpinnings in any significant manner. Polygraph research has proceeded in relative isolation from related fields of basic science and has benefited little from conceptual, theoretical, and technological advances in those fields that are relevant to the psychophysiological detection of deception.
George W. Maschke
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Hunter

I posted a model policy statement from the APA and now we have the NAS report again posted.  You are very much on the defense and I don't care to debate that report with you, it is history and advances have been made as a result of that particular report, and will continue to be made.  

You have posted that:

"Unfortunately many, if not most, law enforcement agencies with pre-employment polygraph screening programs (including all federal ones) will disqualify an applicant based on a failed polygraph alone."

Do you have any studies to back up that statement?  I have found none.  Departments I have spoken with attempt to find the truth through investigation and polygraph, polygraph being the last portion of the process.  If you are deceptive on the polygraph, further investigation is conducted to attempt to clear the case or applicant if we are talking about pre employment.  You are not convicted on the basis of a polygraph and you are not denied employment based on polygraph alone.

I am not looking for debate, and will not enter into one with you.  

1904

Quote from: Hunter on Nov 06, 2007, 11:03 AM

I posted a model policy statement from the APA and now we have the NAS report again posted.  You are very much on the defense and I don't care to debate that report with you, it is history and advances have been made as a result of that particular report, and will continue to be made.  

From That NAS Report that you would like to 'wish away':

Research Progress Research on the polygraph has not progressed over time in the manner of a typical scientific field. It has not accumulated knowledge or strengthened its scientific underpinnings in any significant manner. Polygraph research has proceeded in relative isolation from related fields of basic science and has benefited little from conceptual, theoretical, and technological advances in those fields that are relevant to the psychophysiological detection of deception.


Quote
Do you have any studies to back up that statement?  I have found none.

Dude. dont you read any news at all ?


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