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Polygraph and CVSA Forums >> Polygraph Procedure >> The Scientific Validity of Polygraph
https://antipolygraph.org/cgi-bin/forums/YaBB.pl?num=1011498360 Message started by J.B. McCloughan on Jan 20th, 2002 at 6:45am |
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Title: The Scientific Validity of Polygraph Post by J.B. McCloughan on Jan 20th, 2002 at 6:45am
This message thread is being started in direct response to George Maschke?s assertion that, "CQT polygraphy has not been shown by peer-reviewed scientific research to differentiate between truth and deception at better than chance levels of accuracy under field conditions. Moreover, since CQT polygraph lacks both standardization and control, it can have no validity."
The discussion will encompass but not be limited to; 1. All studies that are published and peer reviewed in a professional journal or publication. 2. Comparisons of polygraph to other scientific accepted fields of studies and their practices. |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Jan 20th, 2002 at 6:50am
I will start the discussion by referencing those interested to a web site that contains government reviews of polygraph and many of the studies and finding on the validity of polygraph: http://fas.org/sgp/othergov/polygraph/ota/
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Jan 22nd, 2002 at 8:04am
Here is an excerpt from http://fas.org/sgp/othergov/polygraph/ota/conc.html to get the discussion under way.
In reading this, one can see that the reviewing entity states quite clearly that polygraph does show a better than chance ability to detect deception. "The preponderance of research evidence does indicate that, when the control question technique is used in specific-incident criminal investigations, the polygraph detects deception at a rate better than chance.." Quote:
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Title: Re: The Scientific Validity of Polygraph Post by George W. Maschke on Jan 22nd, 2002 at 11:57pm
J.B.
You argue that the 1983 OTA report "states quite clearly that polygraph does show a better than chance ability to detect deception." And you cite the following from Chapter 7 of the report: Quote:
As a preliminary matter, note that this statement by the OTA is not inconsistent with my statement that CQT polygraphy has not been proven by peer-reviewed scientific research to differentiate between truth and deception at better than chance levels of accuracy under field conditions. The OTA relied on both field studies and analog (laboratory) studies. Of the field studies, only two appeared in a peer-reviewed scientific journal: Bersh, P. J. "A Validation Study of Polygraph Examiner Judgments," Journal of Applied Psychology, 53:399-403, 1969. Horvath, F. S., "The Effect of Selected Variables on Interpretation of Polygraph Records," Journal of Applied Psychology, 62:127-136, 1977. (By the way, the FAS website does not include the OTA report's list of references. You'll find it in the PDF version available on Princeton University's Woodrow Wilson School of Public and International Affairs website.) Bersh's study involved both the Zone [of] Comparison "Test" (a form of probable-lie "Control" Question "Test") and the General Question "Test" (a form of the Relevant/Irrelevant technique). The polygraphers used "global" scoring, that is, they reached their determinations of guilt or innocence based not only on the charts, but also on their clinical impression or "gut feeling" regarding the subject.The decision of a panel of judges (four Judge Advocate General attorneys) was used as "ground truth." Assuming the panel's judgement to be correct, the OTA report notes that the polygraphers' determinations were (overall) 70.6% correct with guilty subjects and 80% correct with innocent subjects. David T. Lykken provides an insightful commentary on Bersh's study at pp. 104-106 of the 2nd edition of A Tremor in the Blood: Uses and Abuses of the Lie Detector. Because the discussion we are having of polygraph validity is an important one, I will cite Lykken's treatment of Bersh's study here in full for the benefit of those who do not have ready access to A Tremor in the Blood (which now seems to be out of print): Quote:
As Lykken makes clear, Bersh's study does little to support the validity of CQT polygraphy. The second peer-reviewed field study cited in the OTA report is that by Horvath. In this study, confessions were used as the criterion for ground truth. In Horvath's study, 77% of the guilty and 51% of the innocent were correctly classified, for a mean accuracy of 64%. Lykken again provides cogent commentary regarding Horvath's study (as well as a later peer-reviewed field study conducted by Kleinmuntz and Szucko). The following is an excerpt from pp. 133-34 of A Tremor in the Blood (2nd ed.): Quote:
Again, Horvath's study (and for that matter, that of Kleinmuntz & Szucko) does little to support the validity of CQT polygraphy. In A Tremor in the Blood, Lykken addresses three peer-reviewed field studies that post-date the OTA review. I won't address those studies individually for the time being, but I think it's fair to say that the available peer-reviewed research has not proven that CQT polygraphy works at better than chance levels of accuracy under field conditions. Do you disagree? If so, why? What peer-reviewed field research proves that CQT polygraphy works better than chance? And just how valid does that research prove it to be? The other statement I've made (and you've noted) is that because CQT polygraphy lacks both standardization and control, it can have no validity. You'll find that explained in more detail in Chapter 1 of The Lie Behind the Lie Detector. I'll be happy to discuss it further, but before I do, I would ask whether you disagree with me regarding this, and if so, why? |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Feb 18th, 2002 at 7:46am
George,
The OTA's findings and statements that polygraph is better than chance was based on all available credible research and only acceptable field studies were included. Some suggested research studies were eliminated due to validity and structural problems found upon "peer-review". The Bersh study, although archaic, does much to enlighten the general public and scientific community by producing what I believe to be the first field research study of the ZCT (1961 Backster). There were changes made to the ZCT that could have increased the Bersh study accuracy even further, standardized numeric scoring criteria being one. Bersh examiners' did not solely conduct a "clinical" evaluation of subjects for deception as Lykken suggests. The examiners used a global scoring method of evaluation. This method does uses the charts to discern if one is showing deception to a particular question. Global scoring also includes observations of the subject prior, during, and following the exam, and all the available investigative material. It does puzzles me that Lykken would state, "clinical impressions or behavior symptoms, which, we know from the evidence mentioned above, should not have permitted an accuracy much better than chance." It is a well-known fact that psychologists quite frequently use this very method to come to their professional opinion. Sometimes, if not often, psychologists' opinions are regarding weather a client "truly" believes or is being "truthful" about something they say has happened to them. The psychologist then gives his professional opinion to the aforementioned. I have both seen and heard psycholgists testify to these opinions in court. Unlike polygraph, psychology rarely has physiological data to base or support their inferences. As for the results of the study, the OTA compares Bersh?s to Barland and Raskin?s study. The OTA does note that the two studies have some inherent differences. However, the OTA considered the studies similar enough to compare. The OTA states, "Assuming the panel's decisions, the two studies' results are strikingly different. Barland and Raskin attained accuracy rates of 91.5 percent for the guilty and 29.4 percent for the innocent subjects; comparable figures in Bersh's study are 70.6 percent guilty correct and 80 percent innocent correct." My math shows a combine accuracy rate of 81.05 percent for guilty, 54.7 percent for innocent, and 67.87 percent overall accuracy for the two studies. The OTA then wrote, "It is not clear why there should be this variation?.." They go on to give some possible but miss some technical reasons for the differences in the findings of the two studies. Most obvious, Bersh?s study used ZCT and R&I, the global scoring method, and eliminated inconclusive exams. Ground truth is the most difficult element to establish in a polygraph research study because it is subjective to the interpretations and opinions of the peer-reviewer. The R&I question format has proven to be a less accurate technique when compared to the ZCT or CQT in specific criminal issue examinations studies. This is arguably the reason why the Army Modified the General Question Technique (MGQT) to include comparison questions, zone/spot scoring, and total chart minutes. How the two question formats in Bersh?s study compared or differed in accuracy would be interesting. The available scientific research for polygraph shows that a greater percentage of inconclusive exams are found in the innocent. Thus it would be prudent to ascertain that Barland and Raskin's study may have produced similar, if not better, results in the truthful and in the deceptive when compared to Bersh, if inconclusive results were set aside. The scientific community often holds inconclusive results against polygraph when reviewing its scientific validity and accuracy. However, polygraph examiners view inconclusive results as not enough in the chart tracings to determine an opinion. An inconclusive can be attributed to many variables. One example of inconclusive chart tracings may be found in an exam where the examinee has problems remaining still or intentionally moves. Even Farwell the Brain Fingerprint?s inventor says his instrument will produce inconclusive results if the examinee does not remain still during the examination. Lykken also states, "Because the exams were clinically evaluated, we can be sure that every test that led to a confession was scored as deceptive." He makes this statement without any supportive documentation, and/or reference to a specific incident within the study where this actually occurred. There is no evidence to support his opinion on this issue. If a confession were to be obtained prior to chart data collection, the exam would have been considered incomplete by the examiner. This is not the case in point in Bersh?s study because inconclusive and incomplete exams were not included. Lykken's argues that Bersh's study is "fatally flawed" because of his prior assertions. He writes, "That the polygraph test frequently produces a confession is its most valuable characteristic to the criminal investigator, but the occurrence of a confession tells us nothing about the accuracy of the test itself." I agree that a confession is a valuable tool in a criminal investigation. I disagree with his fallible knowledge of the use of a properly documented confession to ascertain conformation of the polygraph data results. A proper confession covers the elements of the crime and includes information that only a person who committed the crime would know. When this information is present in a confession, it would undoubtedly confirm the data. The question here is not weather the confession can be used to confirm the polygraph chart data but what standard was used in deeming statements made by examinee's as a confession. However, this point is not asserted and/or proven in Lykken's argument, thus it would appear to be a nonexistent flaw. Horvath's research study provides good data in areas but had missing information that might of hindered the overall accuracy results. Barland submits that Horvath's original examiners were 100 percent correct in their opinions. Barland notes that some special charts administered in 32 percent of the cases were removed from the files of considered deceptive subjects. These special charts were most likely removed to avoid pre-judgment by the research evaluators. I do not think his study invalidated polygraph in anyway. The study in fact provided valuable insight into the possible effect incomplete chart data might have on accurate review. Horvath's study still produced better then chance results considering there was a 50% chance of the reviewers being correct and they were overall 64% correct. Lykken states, "The original examiners in these cases, all of whom used the Reid clinical lie test technique, did not rely only on the polygraph results in reaching their diagnoses but also employed the case facts and their clinical appraisal of the subject's behavior during testing." This statement is partially true but not completely factual. The examiners in this study used scoring of the charts along with the global information present. The global scoring method in no way goes against the chart data results and contrariwise uses other information to confirm the chart data. Lykken goes on to purport, "Moreover, some other suspects, judged truthful using global criteria, could have produced charts indicative of deception." This is an illogical statement. He never stipulates what scoring method or criterion might have produced a deceptive result. He cannot prove or disprove his assertions. I could easily conclude that, if given all the data available to the original examiners and the same scoring method, the reviewers would have concurred with the original examiners in 100% of the cases. Neither Lykken nor I can prove or disprove our assertions because this variable was not present or measured. However, Barland had access to and reviewed the data after the missing variable was discovered. The point I am making is that no matter how meticulous one accounts for variables there will most likely be ones that need further research to answer. This is true in any research including physiology, psychology, and medical. One cannot control for and/or predict every possible variable. Because a variable is in question does not invalidate the findings or methodology. Because DNA's sample database is relatively small in comparison with the total population that inhabits the earth, does not lead scientists to doubt the accuracy and/or scientific validity of its methods or findings. I have read chapter one of The Lie Behind The Lie Detector and have found no reference to what standardization and control the CQT lacks. You state that it lacks these elements but give no examples or criterion for standardization and control. I would think this would be hard for you to do, as even the scientific community is quite subjective in their opinion of what constitutes acceptable standardization and control for scientific validity. Can you reference, for comparison purposes, any other scientific method that has been accepted and its basis for acceptance? Can you reference, for comparison purposes, any other scientific method that was rejected based on comparable factors you might use to make this statement? |
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Title: Re: The Scientific Validity of Polygraph Post by George W. Maschke on Feb 18th, 2002 at 10:38am
J.B.,
Before I address your questions, I note that you didn't really answer mine: 1) Do you agree that that the available peer-reviewed research has not proven that CQT polygraphy works at better than chance levels of accuracy under field conditions? If not, why? What peer-reviewed field research proves that CQT polygraphy works better than chance? And just how valid does that research prove it to be? I realize you averaged the Bersh and Barland & Raskin studies to come up with an average accuracy of 67.87? Do you seriously maintain that these two studies prove that CQT polygraphy works better than chance and that it is 67.87% accurate? By the way, you did not specify to which study by Barland & Raskin you were referring. I assume you are referring to the following non-peer-reviewed study discussed at p. 52-54 of the OTA report: Barland, G.H., and Raskin, D.C., "Validity and Reliability of Polygraph Examinations of Criminal Suspects," report No. 76-1, contract No. 75-N1-99-0001 (Washington, D. C.: National Institute of Justice, Department of Justice, 1976). 2) Do you agree that because CQT polygraphy lacks both standardization and control, it can have no validity? If not, why? Now, you mentioned that you read Chapter 1 of The Lie Behind the Lie Detector and found no reference to what standardization and control the CQT lacks. That reference is found at pp. 2-3 of the 1st digital edition, where we cite Furedy: Quote:
Other uncontrolled (and uncontrollable) variables that may reasonably be expected to affect the outcome of a polygraph interrogation include the subject's level of knowledge about CQT polygraphy (that is, whether he/she understands that it's a fraud) and whether the subject has employed countermeasures. You asked, "Can you reference, for comparison purposes, any other scientific method that has been accepted and its basis for acceptance?" I think Drew Richardson gave a good example in his remarks to the National Academy of Sciences on 17 October 2001, when he compared polygraphy to a test for a urinary metabolite of cocaine: http://antipolygraph.org/nas/richardson-transcript.shtml#control The test Dr. Richardson describes is genuinely standardized and controlled, unlike polygraphy. You also asked, "Can you reference, for comparison purposes, any other scientific method that was rejected based on comparable factors you might use to make this statement?" For comparison purposes, look to polygraphy's sister pseudosciences of phrenology and graphology. |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Mar 3rd, 2002 at 9:00am
George,
To answer your first question, no I do not agree. The peer-reviewed research does prove polygraph to be better then chance at detecting deception. I purposefully used a rather dated research for my first post because even it provides a better then chance accuracy in the review method used. If we look at Bersh's study alone, "....70.6 percent guilty correct and 80 percent innocent correct.", the overall accuracy rate is 75.3%. This is one of the first field polygraph studies. There have been changes made to polygraph which have improved the overall accuracy, some of which I discussed in my previous post. Bersh?s study also uses non-polygraph evaluators to confirm results. Thus, the 75.3% accuracy is achieved in part through information independent of the polygraph data. Lykken?s argument is that the results are independent of the polygraph charts. I have stated previously that this is not completely true. Some of the evaluators? based their decisions on information independent of the polygraph charts. However, the examiners? original decisions were based on the polygraph chart data. Regardless of all that, it shows better then chance in detecting both truth and deception in a field setting. The combined studies of Bersh and Barland and Raskin do not illustrate polygraph to be 67.87% accurate per se. The studies illustrate that polygraph was accurate to this degree for the particular confirmation method used. Your argument is that polygraph is "not better then chance". Although the previous studies do not reflect the current accuracy rate of polygraph, using the given confirmation method the combine studies do support a better then chance accuracy rate. On a related but separate note, just because Barland and Raskins study did not appear in a professional journal upon its release does not mean it was not peer-reviewed and accepted. Just because Lykken does not like the results and the method is not his, does not make the study invalid. You may get some of the people to agree some of the time but you can?t get all of the people to agree all of the time. Since I have stated that there were improvements made to polygraph which have increased its? accuracy, I will quote some more recent studies to support the increased accuracy of Polygraph. All of these studies appear in professional journals and provide better then chance results for CQT polygraph detecting deception. Quote:
You ask how valid it shows polygraph to be. It is you who have purported that the CQT is not better then chance at detecting between truth and deception. Since you have in the past set the terms for rational discourse, I see it to be your burden to prove what is chance and what peer-reviewed studies have proven polygraph to be below the chance level. You would also have to establish what scientifically the chance level is. In a separate message thread you wrote: Quote:
This is an estimation of base rate on your part. One cannot establish an ultimate true base rate in a field setting for truthful and deceptive because it will vary. One cannot control for the number of cases that will produce one or the other result within a field setting. A toxicologist cannot say that 50% of his cases will detect a presents of XYZ in the field because it will vary. A toxicologist can say that if XYZ is present then it will be detected, if the test works. Since polygraph measures for deception, polygraph can only produce one of two results, if the test works. Thus, the exam/test will have a 50% chance of producing deception or no deception, if the test works. If the exam/test does not work in either discipline, there is an outside contaminant that is thwarting the ability of the exam to produce an acceptable result. As for your second question, no I do not agree that polygraph lacks both standardization and control. Standardization: The instrumentation must meet a standardized criterion. The examiner must meet a specified standard criterion. There is a very standardized process followed in a specific issue polygraph that is discussed in you book. The examiner must follow the process from the beginning to the end. This is standardization. The given question formats must contain a standardized number of a given type of question. This is another standardization. The given question format must follow a standardized sequence. The chart tracings must be of a certain standard of quality for acceptable scoring purposes. The scoring must be done in an acceptable standardized scoring method and must meet a standardized scoring result to make a decision. The fact is that there are numerous standardized methods within polygraph that prove it to be standardized. Control: The examiner is required to conduct the polygraph in a sterol environment that is free of visual and audio distraction. The examiner is required to assess the examinee?s medical background to control for outside contaminants that may hinder the ability of the instrument to obtain suitable tracings. The examiner must attempt to control for movement by the examinee to control for outside contaminants that may hinder the ability of the instrument to obtain suitable tracings. The examiner must conduct an acquaintance exam to control for the possibility of undisclosed medical of physical variants that may contaminate or hinder the ability of the instrument to obtain suitable tracings. Again, polygraph controls for a number of variables and thus does not lack control. You quiet frequently use Furdey and Lykken for references. It should be noted that both of these individuals do have motive to be bias in their opinions toward CQT but support polygraph. Dr. Furedy has repeatedly condemned the use of polygraph but only the CQT method. Furedy is a proponent for polygraph when it uses the Guilty Knowledge Test (GKT). The GKT lacks the extensive research, reviews, critical debate, and sheer numbers of its use in the field setting that the CQT has endured and produced over time. Lykken is under the same ideology as Furdey. Their bias may be genuinely for scientific purposes but I think not. Their motive more likely is synonymous with the old cliché that plagues polygraph, "My question format is better then yours." Why argue so intensely over this issue of the question format to use? Polygraph is attempting to even further standardize an already standardized method. Searching for further standardized format, polygraph looked to the academic community because of its? wealth of resources, ability to formulate experimental design, and ability to conduct extensive controlled laboratory research on the methods. In the academic community, those who posses the acceptable methods are the ones who get the research grant money to perfect and substantiate their methods. This may be somewhat of an off issue for this discussion. However, if one looks at why polygraph has not been overwhelmingly accepted in the scientific community regardless of its? high validity marks, one can see that lack of agreement is a major issue that hold up is overall acceptance. I have spoken with scientists, psychologists, and many other scientific disciplines. These people say that polygraph is valid, not flawless. Again, the reoccurring theme that hinders polygraph is the lack of agreement amongst the ranks. The irony is that those who are causing such confusion and thwarting the acceptance of polygraph as a standardized scientific method are the ones who were sought out to aid in doing just the opposite. Further, these individuals are not even polygraph examiners. "Those who can do. Those who can?t teach." Further more, Lykken?s argument against presence of standardization and control in polygraph is elusive babble. He say?s things like, "There are virtually an infinite number of dimensions along which the R [relevant] and the so-called "C" ["control"] items of the CQT could differ. These differences include such dimensions as time (immediate versus distant past), potential penalties (imprisonment and a criminal record versus a bad conscience), and amount of time and attention paid to "developing" the questions (limited versus extensive). Accordingly, no logical inference is possible based on the R versus "C" comparison. For those concerned with the more applied issue of evaluating the accuracy of the CQT procedure, it is the procedure?s in-principle lack of standardization that is more critical." He has haphazardly taken terms used in polygraph, thrown them about into a paragraph, imposed his own opinion of there meanings and uses without reference to support, and finally drawn a conclusion that has nothing to do with the previous statements made. The fact is, none of Lykken?s gibberish has a thing to do with the standardized methods of polygraph and/or even the physiological data for which its? findings are based on. You state: Quote:
I can with quite certainty say that you have no research or data to support your opinion on this issue. There are no published research studies that have measured specifically for this variance you speak of and/or one that has concluded with data that will concur with your ideology. You then use Dr. Richardson?s explanation in attempts to illustrate a scientific procedure that has been accepted and its? basis for acceptance. Quote:
You will notice in Drew?s explanation that he states, "if the test works". To be fair, maybe all forensic sciences should be put to the standards of validity measurement that is held against polygraph, inconclusive results included. It is a known fact that even controlled testing for proficiency purposes in accepted scientific practices can often go a rye. When this happens, the results can be inconclusive and/or even false. For example I will give a hypothetical scenario; A standardized control sample of urine leaves an accredited proficiency testing company. That sample is known to contain benzoylecgonine. The test is weather the sample contains benzoylecgonine or not. During the shipping process the cabin of the airplane that contains the samples loses atmospheric pressure. The loss of pressure causes the cabin temperature to plummet to -80 degrees F. When the airplane descends, the cabin pressure and temperature returns to normal atmospheric conditions for the region, let us say 70 degrees F for this hypothetical scenario. This change can happen quite quickly considering the sometimes rapid descent of airplanes. The sample arrives at the lab and is tested. It is found to contain no presence of benzoylecgonine and is reported as such. Drew also speaks about the test for known to verify the test and the instrumentation works. A polygraph examiner should be conducting an acquaintance exam/test, as stated in APA polygraph procedures outline. This exam/test checks for the ability of the test to work. If the subject has an autonomic response to the known lie, the test works. If the subject does not have an autonomic response to the known lie, the test does not work. The subject is instructed not to move and to follow specific directions. If the subject does not cooperate and attempts to augment his responses in any way on this non-intrusive exam/test, the subject is intentionally attempting to hide his natural responses. I know of only one reason for someone to augment his or her response. That is, they are going to attempt to deceive. I believe any reasonable person would come to the same conclusion. Now if the exam/test works, I have a true physiological response created by a known lie and a true homeostasis or tonic level measurement contained in the known truth. This data can be used to confirm the remainder of the exam/test data collected. You referenced, for comparison purposes, phrenology and graphology. Phrenology and graphology measures no known and/or research proven methods. These once experimental methods do not even remotely compare to polygraphs extensive research, documentation of known and proven physiological responses, and proven accuracy. A closer but distant comparison you may have used would be questioned documents, since it is a forensic science. From your same source of information, http://www.skepdic.com/graphol.html , the following appears. "Real handwriting experts are known as forensic document examiners, not as graphologists. Forensic (or questioned) document examiners consider loops, dotted "i's" and crossed "t's," letter spacing, slants, heights, ending strokes, etc. They examine handwriting to detect authenticity or forgery." I believe the author of this site accepts questioned documents as a scientific discipline. Polygraph measures known physiological responses of the subject to detect deception. Polygraph has provided more favorable research, standardization and validity then questioned documents. I know you have read the research study in which polygraph was putt head to head against questioned documents and latent fingerprints. Although it is not my burden to prove the validity, I will give an example of how polygraphs tested validity stands up against other accepted science: Quote:
Considering the above, I would conclude that polygraph has provided more then sufficient overall accuracy data and done so over a greater test period of both laboratory and field settings to prove scientifically valid. Comparison example: Quote:
The above comparison supports the assertion that polygraph when using the CQT meets standard validity test requirements to be considered a scientific test method. |
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Title: Re: The Scientific Validity of Polygraph Post by Drew Richardson on Mar 3rd, 2002 at 7:25pm
J.B.,
I believe you have totally missed the point regarding scientific control and what constitutes it in a given instance. It should not be confused with other issues, nor should its absence in one paradigm be confused with the possibility of its isolated absence in the face of operator error in the case of a discipline which in fact normally reflects principles of scientific control. With regard to the first--although it is proper and admirable that polygraph examiners calibrate their instruments, there is little question that electrons do flow and pressure gauges can accurately measure pressures in most instances. Nor is there any serious question that ambulatory individuals who travel to and report for polygraph examinations have at least minimally functioning autonomic systems. The ANS is required on a daily basis for individual life function and its function as displayed in polygraph examinations is trivial relative to its various life sustaining functions. And if autonomic function and responsivity were in question, the re-named so-called "acquaintance test" is no serious measure of it, but merely a nomenclature evolution of the parlor game and fraudulent exercise we have all come to know as a "stim test." To suggest that this is anything more should be embarrassing to one who understands anything about autonomic physiology. As has been pointed out recently by others, the acquaintance test is actually the first opportunity for the examinee to con the con-man examiner with countermeasure response to the chosen number and feigned amazement at the examiner's mystical deductive powers in pointing out said response(s)... But on to meaningful scientific control and that which is lacking with control question test polygraphy... That which will define scientific control in an analysis is the ability of the control to shed light on the various dependent measure recordings of the analyte in question. In the case of the control question polygraph exam, the analyte in question is the relevant question subject matter; the dependent measures are those measures of physiology recorded, and the scientific control, in theory, is furnished by the control or comparison questions. THIS IS WHERE THE HEART OF CONTROL LIES AND WHY IT IS COMPLETELY ABSENT IN PROBABLE LIE CONTROL QUESTION POLYGRAPHY. In order for it to exist, we would need to know something about the emotional content or affect and the relational nature of this affect for chosen relevant and control question pairings within a given exam. Although polygraphers have speculated about this, there is NO independent measure of this for a relevant/control pair for given examinee (guilty or innocent) on any given day. This is not a function of isolated operator/examiner error that you correctly suggest could exist on any given day with any discipline, but is an every day condition and lack of control that exists with polygraphy. If an innocent examinee is not more concerned with control/comparison questions than relevant questions (i.e. the emotional content/affect of controls is greater than for relevant questions) and this can not be demonstrated through the process, then any recording of physiological response (dependent variable) and any conclusions drawn are absolutely meaningless with a given exam. This inability to verify theoretical constructs with a given relevant/control pairing for a given examinee is what makes control question test polygraphy without scientific control and without any ability to be meaningfully analyzed. This situation does not exist with the forensic toxicological analysis that you either completely do not understand (hopefully) or intentionally misrepresent. The chemical/physical relationship between deuterated-benzoylecgonine (control) and benzoylecgonine (urinary metabolite of cocaine and analyte of interest) is well understood for all of the environments involved in analysis, i.e., tissue, organic and aqueous media, chromatographic packing materials, mass spec source, analyzer, etc. Because of this one can determine whether an experiment worked and what qualitative and quantitative conclusions can be meaningfully deduced with any dependent variable measurements obtained. To compare control question test polygraphy to this is, again, a quite embarrassing comparison. Again, the fact that operator error can compromise the validity of quality control or operational practice with any given toxicological analysis neither makes this (forensic toxicology) uncontrolled under normal circumstances nor vicariously makes control question test polygraphy more of a scientifically controlled practice through any contrived and envious comparisons. It most assuredly does not. WE ARE LEFT WITH WHAT WE BEGAN WITH---PROBABLE LIE CONTROL QUESTION TEST (CQT) POLYGRAPHY DOES NOT IN ANY WAY EMBODY PRINCIPLES OF SCIENTIFIC CONTROL... |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Mar 7th, 2002 at 10:09pm
Drew,
Although one may control for some given variants in a particular setting, there is always the chance of uncontrollable variants. I will admit I am not a toxicologist. My knowledge of this discipline is extremely limited in comparison to yours. I am not arguing that toxicology is invalid nor is that the subject. I did not use or list toxicology as a direct comparison of scientific validity. My reference to toxicology was to show that even validated disciplines could have outside factors that cannot be controlled for in field settings and that those outside factors may produce an inconclusive and/or false result. I compared questioned documents for scientific validity and I used documentation of the validity results of the 3T3 NRU PT for accuracy comparison. This dialog was in direct response to what George wrote in his post prior to mine. Quote:
In reading this I deducted George was referring to variant control. George must prove, with substantiated evidence of comparable scientific disciplines, that polygraph is not scientifically valid. It is his assertions and this discussion is based on those and the past rules of discourse he has used. I wrote, “This exam/test checks for the ability of the test to work. If the subject has an autonomic response to the known lie, the test works. If the subject does not have an autonomic response to the known lie, the test does not work.” I did not say that the purpose of the stim/acquaintance was to measure the ability of the ANS to work. A positive control test simply takes a known sample of a suspected unknown and simultaneously tests it with the unknown. For example: Quote:
You reference the ANS. Although the ANS is regularly used to sustain life, the specific deceptive ANS response measured in a polygraph is not regularly used for continual life sustaining purposes. I agree with you that there are other reasons that you have alluded to that define others’ explanations for the use and existence of the stim/acquaintance test/exam. A stim/acquaintance test/exam is a Known Solution Peak of Tension Test. Polygraph examiner training material reads as follows in reference to the stim/acquaintance, “Correlate outcome to the polygraph examination.” Given my and the above supporting literature’s explanation of positive control test, do you agree or disagree that the stim/acquaintance test/exam is a positive control test? Quote:
When referring to scientific validity, one can reference many instances where a science was discredited by the majority of scientists, thus not accepted, and inversely proven to be true and accepted at a later date without addition and/or change to theory. The reverse of this process has also happened. So “Scientific Validity” is in itself a highly subjective process directly dependent on the opinions of the current majority of scientists in the related discipline. A scientific process can be accurate and its theory sound but with an absence of its general acceptance it may be considered invalid. It is the test of scientific acceptability that defines whether a theory or practice is accepted. |
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Title: Re: The Scientific Validity of Polygraph Post by George W. Maschke on Mar 7th, 2002 at 11:42pm
J.B.,
In your post of 3 March, you wrote in part: Quote:
J.B., my argument is not that polygraphy is "not better than chance," but that it has not been proven by peer-reviewed research to work better than chance under field conditions. And in your post of 7 March (today) you write: Quote:
No, J.B. The burden of proof rests with you (and other polygraph proponents) if you would have us believe that CQT polygraphy is a valid diagnostic technique. Respectfully, I don't think you've met that burden. Not even close. |
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Title: Re: The Scientific Validity of Polygraph Post by beech trees on Mar 8th, 2002 at 12:48am J.B. McCloughan wrote on Mar 7th, 2002 at 10:09pm:
Nope, no sir. No way. You cannot prove a negative, it is a Logical impossibility. The burden of proof rests squarely on your shoulders. Thus far, I'm not convinced. |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Mar 8th, 2002 at 8:06am
George,
This thread was started because of a direct statement that you had made about polygraph. You said, "CQT polygraphy has not been shown by peer-reviewed scientific research to differentiate between truth and deception at better than chance levels of accuracy under field conditions. Moreover, since CQT polygraph lacks both standardization and control, it can have no validity." You have in no way supported this assumption. Lykken or any other opponent of CQT polygraph has not proven your assumption. There is no current statistical data in field or laboratory peer-reviewed research studies that purports polygraph is not better then chance accuracy at differentiating between truth and deception. I have supported this by illustrating some current and past peer-reviewed studies all with higher then chance validity rates and the more current with validity rates equal to or better then some of the accepted scientific disciplines. You and those you reference write of the lack of scientific control and standardization yet there is no support for these assumptions. They are simply unsupported statements. Lykken does have the afforded luxury of being renowned in his field. Thus his assertions are reverend by the followers of his ideology(GKT). His arguments only aid in the slowing of general acceptance and do nothing to disprove polygraph as a scientifically valid discipline. You do not have the afforded luxuries that Lykken does. Your formal education is not in a related or even semi-related field. For you to make unsupported statements with the lack of credential or peer-reviewed research to support these is nothing more then a lay assumption or repeat of Lykken's meaningless rhetoric. I have shown examples of scientific control, standardization, and validity. I have reviewed my comparisons with scientists of other accepted disciplines and they believe my explanations are sound scientifically and support my assertions. I again ask you: 1) What about the current peer-reviewed field researches show polygraph to be no better then chance accuracy and what is the current accuracy rate? 2) What control does polygraph lack? 3) What standardization does polygraph lack? If you cannot prove your assertion, then please retract it and state that which you can support with hard evidence. beech trees, This debate is in reference to an assertion made by George. He has in the past set the rules for rational discourse and placed the burden of proof on he who makes the assertion. Thus, the burden of proof is his. This is not a scientific review of polygraph for official acceptance. If that were the case, I would agree with you that the presenter of evidence of a purposed science for acceptance would have the burden to prove it to be true. There are very few on this site who have the credentials to carry this type of formal debate out and it would have to be done in proper forum for acceptance. |
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Title: Re: The Scientific Validity of Polygraph Post by Drew Richardson on Mar 8th, 2002 at 4:16pm
J.B.
Quote:
True, but irrelevant to the fact the probable-lie control question test (CQT) polygraphy has no, nada, zilch scientific control on ANY day, uncontrollable variants notwithstanding. This is because the emotional content of relevant/control question pairings is NEVER known apriori for a given examinee with a given examination. This makes any conclusions drawn from physiological recordings meaningless and sheer speculation on each and every occasion/outing. Quote:
Again, all likely true, and although containing an appreciated and flattering admission, all irrelevant to the issue at hand... The theoretical nature of control/comparison questions (emotional content/affect in relationship to paired relevant question material) can not be verified on ANY and again I repeat ANY given occasion, making their use, if not without purpose, at least providing no scientific control in any formal and recognized context. |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Mar 8th, 2002 at 10:44pm
Drew,
Quote:
Do you agree that the POT/Known Solution Test can be considered as a Positive Control Test or not? |
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Title: Re: The Scientific Validity of Polygraph Post by Drew Richardson on Mar 8th, 2002 at 11:16pm
J.B.,
In order to answer your lasted posted question, I am afraid I must seek clarification. I believe that you are asking me if I consider the stim/acquaintance test a positive control for subsequently administered probable lie control question tests. If not please correct me, and I will answer your intended question. But to this one... No, I don't---if the stim/acquaintance test were in fact a probable lie CQT, at best, you would have an external control situation, a much weaker form of control than the internal positive control we have discussed with a forensic toxicological analysis, but in fact, even this weaker form of control does not exist... The so-called stim test is really not a probable-lie CQT or any other test for deception and therefore offers no form of control, external or internal. The reason being that, although you can instruct the examinee to answer "no" to the chosen number (and therefore lie), you can also have he/she answer "yes" to that same number or provide no answer at all, i.e., a silent test, and obtain exactly the same result/same response. In other words, the lie is irrelevant to the stim test and what the stim test really is is a form of concealed information test in which the examinee is merely responding to something of significance to himself, significance derived from the fact that the number was recently chosen by the examinee. Although, as I have indicated before, I have great disdain for how a stim/acquaintance test is used in a polygraph setting, I actually believe the format, apart from that setting, to be a quite useful and a narrowly defined/controlled vehicle for studying physiological change. But again, in answer to the question that I believe I was asked, it (a stim test) has absolutely nothing to do with providing control to a probable-lie control question test. |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Mar 8th, 2002 at 11:57pm
Drew,
You have I think answered my question. Regardless if the polygraph format is CQT, GKT, or R&I, the Stim/Aquaintence test (otherwise known as the POT/Known Solution Test) is a positive control test. As for Comparison/Control Questions, I believe that these will fall under the same defenition of standard tests. So now we have a positive control and a standard test being used in a CQT polygraph, the same tests that are used in other accepted scientific disciplines. I will be traveling for the weekend. So I may not respond to you further for a couple of days. |
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Title: Re: The Scientific Validity of Polygraph Post by Drew Richardson on Mar 9th, 2002 at 12:07am
J.B.,
I am glad I responded to your question; unfortunately, you do not appear to have read my answer. I really don't want to be flippant with you, but you appear to have no knowledge of the terms and practices that you associate in your writings. But nevertheless, do enjoy your weekend and we can continue anew next week... |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Mar 12th, 2002 at 6:00pm
Drew,
In looking at my last post, I can see that one of the terms was used without explanation and could have been misconstrued in the meaning of its use. Standards are samples with a known identity that unknown are being compared to for identification. To determine that a method is working correctly, one must use appropriate controls and standards. One may use quantitative controls (called blanks), blind controls and/or internal controls. These controls are used to assure a reproducible and accurate method by which an acceptable value or range of values is established. Irrelevant questions are blanks. Control/comparison questions are suspected known samples that can be established with the known sample from a stimulation/acquaintance test. The relevant questions are unknown samples that are compared with the other test data to establish its degree within the range of values. If the degree is consistently greater in the relevant questions, set by numerical scoring criterion, then deception is shown. |
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Title: Re: The Scientific Validity of Polygraph Post by Drew Richardson on Mar 12th, 2002 at 11:40pm
J.B.,
There is not the slightest bit of scientific control furnished through the utilization of comparison questions with a CQT. In order for there to be, there would need be some CLEARLY DEFINED, CONSISTENT AND READILY DEMONSTRABLE relationship between the affect of the two types of stimuli. NO SUCH RELATIONSHIP EXISTS. Furthermore, the comparison questions of a CQT have no relationship to the alternative (or correct) answers of a stim/acquaintance test. As I previously pointed out, the latter is merely a concealed information test (at best) whereas the former is suggested by its proponents as having some relationship to detection of deception . Your comparison of apples and oranges and conclusions drawn is most perplexing and somewhat troubling… |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Mar 15th, 2002 at 7:20pm
Drew,
You wrote: (1) Quote:
Although other stimuli may be present, the common and main stimulus that exists between the comparisons and relevant questions is deception. It is the deception that causes the release of hormones from the adrenal medulla. The greater the stimuli the greater the release. Thus, if a stimulus for comparison questions is equal to the stimuli of the relevant questions, there is a valid comparison to be made. Whatever the emotion that is elicited with the deception is a conditioned response and secondary to the main stimuli. The secondary conditioned response will be readily consistent for a given person based on psychosocial conditioning. Support for statement: Quote:
(2) Quote:
The (correct) answers on the stim/acquaintance test are quantitative controls or blanks. They are simply used to establish the homeostasis or tonic level of a given subject. The incorrect/deceptive response to the known lie on the stim/acquaintance test can be used for direct comparison with the responses to the comparison/control questions on the CQT to confirm deception. (3) Quote:
I have already posted a direct quote from polygraph training material. Quote:
In a previous post you wrote: Quote:
In my opinion this and the previously quoted statement are contradictory in nature. Your comment about my comparisons of apples and oranges in unspecified. If you are referring to my definitions of the different scientific controls, then I would agree that it is you who is perplexed. I have discussed these terms, their definitions, and the relationship to the portions of polygraph noted with other scientists within accepted fields and they concur with me. It is not my burden to get you to agree and/or even my burden to prove anything. Scientific acceptance is for the most part general and not specific to an individual. Like I have stated before, the scientific acceptance of any given method is for the most part subjective and opinionated. We are wandering farther and farther of the course of this debate. I do recall it being ‘MY’ burden in the last debate on CMs due to my assertions. This debate is based on George’s assertions. To date he has provided no peer-reviewed scientific research either field or laboratory that proves CQT polygraph to or not to, “…. differentiate between truth and deception at better than chance levels of accuracy under field conditions..” What is the current overall accuracy rate of CQT polygraph shown by peer-reviewed field and laboratory research? |
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Title: Re: The Scientific Validity of Polygraph Post by Drew Richardson on Mar 15th, 2002 at 10:45pm
J.B.
Quote:
Balderdash!!!!! As a former US President was fond of saying, "There you go again..." There is not the slightest bit of evidence of such a thing. Even your more serious colleagues in the world of polygraphy don't claim a "lie response" let alone one uniquely manifested at the level of the adrenal medulla. Remember, my friend, you are talking to a toxicologist. Please show me anywhere in the literature that therapeutic monitoring of blood levels of norepinephrine and/or epinephrine has been performed in connection with deception in a CQT, let alone correlated with deceptive responses to control and relevant questions. As utterly ridiculous and unsupported as this hypothesis is, it totally ignores the sympathetic cholinergic (acetyl choline) electrodermal responses that have nothing to do with the adrenal medulla. It furthermore ignores the timing of the onset of response (seconds) which is consistent with neuronal input (neurotransmitters) not organ bathing over minutes with blood born adrenergic hormones which at best contributes to duration of cardiovascular responses (again even this physical phenomenon has never been shown to correlate in any fashion with deception, isolated from God knows how many other factors involved with the asking of questions in a CQT). This is nonsensical beyond all reason and not worthy of comment, save eliminating confusion for only the most naive who visit this site..... |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Mar 16th, 2002 at 5:24pm
Drew,
This should not a battle of brash words but a debate conducted in a professional manner. I do not appreciate your unwarranted satirical remarks. My statements are supported within professional scientific texts. My prior post used a Social Psychology reference to support my statement about emotions. Here are some support references for the Physiological portions of my statement. Quote:
Quote:
Quote:
Quote:
Quote:
Quote:
(Note: this post was edited by the AntiPolygraph.org administrator to correct a coding problem that affected display of the message thread. No changes were made to the words posted.) |
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Title: Re: The Scientific Validity of Polygraph Post by Drew Richardson on Mar 16th, 2002 at 6:12pm
J.B.
My goal is not to hurt your feelings through sarcasm, but to clearly point out wild leaps of faith on your part as evidenced by your quantum jumps from explanations of reasonably well-understood physiology to your postulates about control question test (CQT) polygraphy. I suppose my language is a reflection of the need to continue this after several such exchanges. Perhaps you can point out to me where deception/detection of deception is discussed in any of that which you have quoted. With the exception of the Seely et al quote (idle speculative commentary (secondary source) with no reference to the scientific literature), I see none. Unless you can, it is completely irrelevant (and would be if you had downloaded a complete physiology text if unrelated to deception through references to the peer reviewed literature) to our discussions and simply more evidence of a lack of critical thinking.... sorry, but there lies the truth. It is not I who stated categorically that adrenergic hormone release was directly and proportionately related to deception, but you. Where's the proof. Absolutely none of that which you have offered in your most recent post is evidence of that...if you are going to idly speculate about such things, so be it, but please distinguish such and identify for the reader and also realize that you have offered nothing whatsoever to indicate that comparison questions in a CQT offer any form of scientific control. (I believe the original issue we were discussing) |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Mar 31st, 2002 at 7:59am
Drew,
First off, my feelings have nothing to do with my last post. Hearing bothersome language and being called names, not on my birth certificate, are common occurrences in my line of work. My point was we are professionals and we should keep the dialog as such. Some of the cites in my last post were directed toward your assertion that; Quote:
So I quoted to that; Quote:
Although Acetylcholine (ACh) is the pre-ganglionic neurotransmitter for both the sympathetic and the parasympathetic divisions of the autonomic nervous system, the post-ganglionic neurotransmitters are different. Norepinephrine (Ne) is the post-ganglionic neurotransmitter for the sympathetic division, which is used for emergency response. Most organs use both the sympathetic and parasympathetic innervation. There are three exceptions to the above and they are; 1. The blood vessels are only sympathetically innervated. 2. The sweat glands are only sympathetically innervated with the use of ACh as the neurotransmitter. 3. The adrenal glands are sympathetically innervated with the use of ACh as the neurotransmitter. I am assuming that this is what you were referring to. If so, I would agree with your last statement in the described neurological portion of a response. There are other factors you negated to discuss, such as the hormonal induced ones. I don't think you were suggesting that neurological functions cannot be effected by hormons. For example: Quote:
Quote:
I own the books I quote and they are not downloaded. I use web-based information because it is readily accessible to anyone who wishes to check my information for accuracy. I can use full text material I own but most cannot check for the accuracy of statements against those sources. Seely is a well respected figure within his field and I dare say has more knowledge of anatomy and physiology then both you and I combine. Deception is a broad term and can be associated with much of the literature available. In an earlier post I cited a book entitled "Social Psychology", which I own, and the quoted text puts the idea of deception into context for our discussion. Quote:
Is the intention of your above statement to suggest that the fight or flight syndrome has nothing to do with polygraph? Are you saying that the sum of stimuli is not proportionately related to the response? Again, deception is a broad-based term that covers many facets. As for your inference to scientific control, I have given you definitions of scientific controls taken from other accepted scientific disciplines' and how the CQT uses them. I am not here to argue which is a better question format, CQT vs GKT. I believe they both have utility and are valid when used in a proper setting. I have already made it known what my thoughts are as to the use of CQT in a pre-employment screening setting. You are correct in that the point of this debate is amiss. George made the assertions that this debate was based on. He has purported that the CQT has not been shown to be better then chance in peer-reviewed field research. This debate has meandered off course because he has changed the subject and passed the burden without first ever proving his assertions. In a separate thread I wrote; Quote:
George then replied, in part, the following answer; Quote:
I think this is what I have been saying all along. CQT polygraph used for specific criminal issue purposes is highly accurate and is scientific. However, some want GKT instead of CQT so they press for its unacceptability and in the course find their cause in the same disarray because it relies heavily on many of the core concepts. If GKT proponents and CQT proponents would simply agree that both of the methods have utility and are valid, then we would most likely have two scientifically accepted formats. More importantly, I cannot imagine the impossible force the combine effort would have in steering polygraph. Still George, you, and I all know that CQT is shown to be better than chance in the current accepted peer-reviewed field research studies. |
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Title: Re: The Scientific Validity of Polygraph Post by George W. Maschke on Mar 31st, 2002 at 1:43pm
J.B.,
You wrote in part: Quote:
Where did I change the subject? I am not aware that I did so. If the polygraph community would have the rest of us believe that CQT polygraphy is a genuinely standardized and controlled diagnostic test that works better than chance under field conditions, then it must shoulder the burden of proving it. As we noted in The Lie Behind the Lie Detector, there are only four field studies of CQT validity that have been published in peer-reviewed scientific journals, and they haven't met the burden of proving CQT polygraphy to work better than chance. (Note that this is not the same as saying that polygraphy has been proven not to work better than chance.) You suggest that the reason CQT polygraphy has not been unanimously accepted by the scientific community is attributable to squabbling over whose format is better (CQT vs. GKT). I suggest a different explanation: a dearth of competent research establishing its validity. With regard to the scientific community's acceptance of CQT polygraphy, I would again remind you of Iacono & Lykken's survey, which is discussed at p. 22 of the 2nd ed. of The Lie Behind the Lie Detector: Quote:
And as for standardization and control, I think you've failed to understand both concepts, as is amply illustrated by your exchange with Drew above and before that, by your dismissal (in your post of 3 March) of Furedy's critique (which you clearly did not understand and mistakenly attributed to Lykken) as "elusive babble." If you would have us believe that CQT polygraphy has been proven by peer-reviewed research to differentiate between truth and deception at better than chance levels, then among other things, you ought to be able to: 1) tell us what the diagnostic sensitivity and specificity of CQT polygraphy is for the detection of deception; 2) cite the peer-reviewed research that establishes such sensitivity and specificity; 3) refer us to the standardized protocol for the CQT that was used in this research; 4) explain how such variables such as whether the subject understands how truth vs. deception is actually inferred in CQT polygraphy and whether the subject employed countermeasures were controlled for. |
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Title: Re: The Scientific Validity of Polygraph Post by Drew Richardson on Mar 31st, 2002 at 2:29pm
J.B.,
The glory of medical physiology does not and will not cover the sins and shortcomings of control question polygraphy. Your use of the former in an attempt to support the latter through wild assertion and speculation will not fly. Please do not waste my time or that of other readers with anything less than citations from the peer reviewed physiological literature with specific reference to control question test polygraphy if you would have me evaluate and draw conclusions about one based on the other… With regard to teaming up with CQT polygraphists, perhaps, but not as you suggest. I will never seek to garner support for the meaningful (e.g., concealed information testing) by generally associating myself with the unsound, unsupported, uncontrolled, and unspecifiable behavior we now know as control question test (CQT) polygraphy. The only faint praise I can presently offer practioners of such in a criminal specific-issue setting is that your practice is theoretically more sound than that of your colleagues who use it for the fishing expedition we have come to know as polygraph screening. But as to your suggestion of team effort…when those of you who use CQT polygraphy in a criminal specific setting have mustered sufficient courage and integrity to openly condemn (It is not sufficient to simply say that my agency does not do polygraph screening) that which you know to be wrong and the source of victimization of thousands of individuals (including many who visit this site), then you will find me quite willing to be part of a team effort to end polygraph screening. I will be more than happy to be a follower of those in your community who will spearhead such an effort and, once the mutual goals of such a team effort have been achieved, I will pledge support to reevaluate with an open mind all the various options for criminal specific-issue testing. |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Apr 1st, 2002 at 8:23am
George,
I was referring to your insistence that I must prove CQT polygraph valid. For example: On 01/22/02 you wrote: Quote:
On 02/18/02 you wrote: Quote:
On 03/07/02 you wrote: Quote:
On 03/30/02 you wrote: Quote:
It is you who has said that, "CQT polygraphy has not been shown by peer-reviewed scientific research to differentiate between truth and deception at better than chance levels of accuracy under field conditions. Moreover, since CQT polygraph lacks both standardization and control, it can have no validity." I repeatedly have asked you how valid the current peer-reviewed scientific field research has shown CQT polygraph to be. Drew interjected with a quiet valid argument about true standards and controls. However, my original references to standardization and controls were based on your wording, "2) Do you agree that because CQT polygraphy lacks both standardization and control, it can have no validity? If not, why???Other uncontrolled (and uncontrollable) variables that may reasonably be expected to affect the outcome of a polygraph interrogation include the subject's level of knowledge about CQT polygraphy (that is, whether he/she understands that it's a fraud) and whether the subject has employed countermeasures." Even so, I continued the dialogue referencing scientific definitions of controls and standards and how they are used in CQT polygraph. I admit I erred in attributing Furedy?s assumptions to Lykken, easily done as they are from like ideological camps. I completely understand what he is saying about the psychological and sociological consequences and elements that may differ in any given test/exam. The survey you posted does not specify what information was given to those who were polled and what prior if any knowledge they had of polygraph. Honts has disputed this poll and I don?t think provides any enlightenment to your original statement for which this debate is centered around. You then ask me once again to prove elements before you establish your assertion of the validity. |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Apr 1st, 2002 at 8:33am
Drew,
Just because there are no direct peer-reviewed researches studies for the CQT polygraph on the physiological responses described does not mean that there are no comparable psychophysiology studies. I don?t see it is necessary to continue this discourse. It is George who has a not better than chance validity assertions to establish. There also currently exists the problem of multiple uses that are shirttailed to one another under the common ground of the CQT format, which may rightfully cause subjectivity problems for almost every inference throughout a continued discussion. I cannot agree with you more about your task for the future of pre-employment polygraph screening. I too do hope that a true combined effort can be established for the betterment of society as a whole and polygraph as a profession in the not so distant future. |
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Title: Re: The Scientific Validity of Polygraph Post by George W. Maschke on Apr 1st, 2002 at 12:22pm
J.B.,
Quote:
This is hardly changing the subject. Quote:
No sensitivity or specificity can be determined for CQT polygraphy (an uncontrolled, unstandardized, unspecifiable procedure) based on the available peer-reviewed field research. Quote:
The survey to which I referred (Iacono, W.G. and D.T. Lykken, The validity of the lie detector: Two surveys of scientific opinion, Journal of Applied Psychology, 1997, 82, 426-433) does indeed specify what information was provided to those who were polled, and your assertion that it doesn't suggests that you haven't read it. If you have the 2nd ed. of Lykken's A Tremor in the Blood: Uses and Abuses of the Lie Detector, you'll also find the information that was provided to survey respondents at pp. 179-181. I only mention this survey in response to your ludicrous assertion that the failure of CQT polygraphy to be unanimously accepted by the scientific community is ascribable to quibbling over whose format is better (CQT vs. GKT). In your last message directed to Drew you wrote: Quote:
Again, I haven't claimed that polygraphy has been proven not to work better than chance, but rather that it has not been proven by peer-reviewed research to work better than chance under field conditions. Your position seems to be that polygraphy is valid until proven invalid. If that is indeed your position, then I think there is little point in further discussion. |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Apr 8th, 2002 at 8:04pm
George,
It is a change of subject. You shift the burden in every discussion and still have yet to assert what the accuracy rate is for CQT polygraph under field conditions. I have read the survey you have cited. What I meant by my prior statement was that the information was not specified and/or included in the cited survey by you. Iacono and Lykken’s survey indicates it is for the purpose of “the evaluation of the validity of polygraphic lie detection”. However, it is overwhelmingly obvious that this survey was conducted in the attempt to discredit CQT and boast GKT. My assertion about squabbling over methods is not ludicrous but a well-known fact that this ideological camp supports GKT and only prescribes ill comments to CQT. If you would have posted the information provided in the survey to those surveyed about the CQT and GKT, one could see that the information was vague and bias. I say vague because there is simply an opinionated summary of the CQT theory. For example; Quote:
There should have been data presented of the accepted research studies validity findings and/or a list of these studies combined to show a statistical overall accuracy rate. A short outline of the entire method should have also been included. I say bias because the wording in the descriptions of the two question formats is obviously slanted. When the CQT is discussed, the physiological response is a “physiological disturbance”. When the GKT is discussed, it is a “physiological response”. When looking at the GKT method description, there are several studies suggested for reference. The CQT method only lists one source and makes no suggestion to references. The difference of the highly informed subject group, who thought CQT was at least 85% accurate, and the remaining uninformed was an interesting point of discussion that was touched but dismissed. The percentages of with opinion on the surveyed areas are also an interesting topic of discussion that is set aside. Whatever you wish to say about chance validity, you still have not once given what the established validity is and/or soundly defined your assertion as to how you have come to the chance validity conclusion. Both the sensitivity and specificity is included in your statement. I assume your assertion is based on the RCMP study. Maybe if you were to say, "CQT polygraphy has been shown by peer-reviewed research to work at not better than chance levels for truth under field conditions.” your assertion may have some grounds, albeit still arguable. My assertion is not that polygraph is valid until proven otherwise. It is that the accuracy rate for the CQT format has been acceptably established when used in a specific criminal issue testing scope and the only element missing is its proof of general acceptance. It has been pointed out in previous literature that one of the main reasons for this lack of scientific acceptance is the lack of universal agreement within the field of polygraph, (ie.. use, question format methods,….) This task is much easier to accomplish by narrowing the scope of use. |
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Title: Re: The Scientific Validity of Polygraph Post by George W. Maschke on Apr 9th, 2002 at 3:44pm
J.B.,
You wrote: Quote:
As I noted in my post of 1 April above, "No sensitivity or specificity can be determined for CQT polygraphy (an uncontrolled, unstandardized, unspecifiable procedure) based on the available peer-reviewed field research." If you disagree, could you tell us, based on peer-reviewed research conducted under field conditions, what the sensitivity and specificity of CQT polygraphy is and refer us to the standardized protocol for the CQT that was used in this research? You also wrote: Quote:
What is ludicrous, J.B., is your earlier statement: Quote:
In Iacono & Lykken's survey of SPR members, only 36% of respondents with an opinion answered affirmatively when asked, "Would you say that the CQT is based on scientifically sound psychological principles or theory?" And 99% of respondents with an opinion agreed with the statement, "The CQT can be beaten by augmenting one’s response to the control questions." I think it's completely absurd for you to suggest that the large majority who did not agree that CQT polygraphy is based on scientifically sound pyschological principles or theory and the overwhelming majority who agreed that the CQT can be beaten reached those opinions because of partisan loyalty to some supposed "ideological camp" that supports the GKT. Nor do I see any reason for supposing that any alleged bias on the part of Iacono and Lykken accounts for the results of their peer-reviewed survey. Clearly, CQT polygraphy's lack of support amongst the scientific community is attributable to something more than just "squabbling between ideological camps as to who's question format is better." |
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Title: Re: The Scientific Validity of Polygraph Post by beech trees on Apr 9th, 2002 at 7:00pm wrote on Apr 9th, 2002 at 3:44pm:
The district court found that there are no standards which control the procedures used in the polygraph industry and that without such standards a court can not adequately evaluate the reliability of a particular polygraph exam... The Court enumerated a series of general observations designed to aid trial judges in making initial admissibility determinations. In ascertaining whether proposed testimony is scientific knowledge, trial judges first must determine if the underlying theory or technique is based on a testable scientific hypothesis. Id. at 593. The second element considers whether others in the scientific community have critiqued the proposed concept and whether such critiques have been published in peer-review journals. Id. at 593-94. Third, the trial judge should consider the known or potential error rate. Id. at 594. Fourth, courts are to consider whether standards to control the technique's operation exist... The reliability of polygraph testing fundamentally depends on the reliability of the protocol followed during the examination. After considering the evi- dence and briefing, the court concludes the proposed polygraph evidence is not admissible under Fed. R. Evid. 702. Although capable of testing and subject to peer review, no reliable error rate conclusions are available for real-life polygraph testing. Addition- ally, there is no general acceptance in the scientific community for the courtroom fact-determinative use proposed here. Finally, there are no reliable and accepted standards controlling polygraphy. Without such standards, there is no way to ensure proper pro- tocol, or measure the reliability of a polygraph examination. Without such standards, the proposed polygraph evidence is inadmissible because it is not based on reliable `scientific knowledge.' USA v CORDOBA 9850082 |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Apr 12th, 2002 at 2:27am
George,
First, where in any peer-reviewed scientific research study has your following assertion been conclusively shown to be true? Quote:
Again, I am not saying polygraph is valid until proven otherwise. I am saying what peer-reviewed scientific research supports that the “CQT polygraphy has not been shown by peer-reviewed scientific research to differentiate between truth and deception at better than chance levels of accuracy under field conditions.” If there is one to support your statement, then what was the specificity and sensitivity established? You then mischaracterized my statements. I wrote: Quote:
In relevant terms you respond: Quote:
Not once have I said and/or suggested that the respondents “who did not agree that CQT polygraphy is based on scientifically sound pyschological principles or theory and the overwhelming majority who agreed that the CQT can be beaten reached those opinions because of partisan loyalty to some supposed "ideological camp" that supports the GKT.” I have not made one mention to this and there is no statistical data to suggest this or its disputed form. The apparent bias in Iacono and Lykken’s study and how it is presented is shown in part by the illustrated points of my previous post. Was all of the data and material of this study made available to Honts, Raskin, et al for critique and criticism, as required? Did the study use consistent scales (ie.. 1-5) for all the questions? Was the cutoff point uniform throughout the different questions (ie.. a ‘5’ response is an ‘agree’ and a ‘1’ response is a ‘disagree’ response for every question asked and answered). How informed were the majority of responders? A good follow-up to this survey would be to provide all the original responders with a detailed presentation of CQT polygraph, conduct the original survey following with an included sub-answer for all methods to each question and see how their responses differ and what their concluding comparative assessment is of the degree of information provided by the original study to the latter. Quote:
Can you illustrate a debate over the scientific support of CQT polygraph where an adversary format is not involved? It seems to be the reoccurring theme of most every discussion revolving around CQT polygraph. Even you use GKT proponents/CQT opponents in your illustrated texts and studies. Quote:
These responses mean little to nothing without knowing the degree of knowledge of the responders. The later response needs additional definition of the augmentation. For example; What is the possibility that one would beat the CQT by augmenting their responses to the control questions? Remember that most anything is possible and/or conceivable but is subject to the given and/or stipulated condition to establish a degree of its probability. Iacono and Lykken’s study just gives the opinion of the responders that it is possible, not how possible and under what conditions. |
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Title: Re: The Scientific Validity of Polygraph Post by George W. Maschke on Apr 12th, 2002 at 7:18am
J.B.,
My conclusion that CQT polygraphy has not been proven by peer-reviewed scientific research to differentiate between truth and deception at better than chance levels of accuracy under field conditions is based on a review of the four peer-reviewed field studies that have been published (and the understanding that CQT polygraphy is an unspecifiable procedure that lacks both standardization and control), not on a peer-reviewed study assessing those studies. (Note, however, that Professor Furedy's critique of the scientific status of CQT polygraphy, cited in Chapter 1 of The Lie Behind the Lie Detector, and which you casually dismissed as "elusive babble," was published in the International Journal of Psychophysiology.) Again, if you disagree with me on this, could you tell us, based on peer-reviewed research conducted under field conditions, what the sensitivity and specificity of CQT polygraphy is and refer us to the standardized protocol for the CQT that was used in this research? Your continued silence on this point suggests that you can't. With regard to the Iacono and Lykken study, again, I only mentioned it to illustrate the point that the lack of unanimous support for CQT polygraphy in the scientific community is not, as you suggested, attributable merely to squabbling over whose technique (CQT vs. GKT) is better. The majority of survey respondents who did not believe that the CQT is based on scientifically sound psychological principles or theory cannot plausibly be argued to have based their skepticism regarding CQT polygraphy on some imputed advocacy for the GKT. |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Apr 15th, 2002 at 7:27am
George,
1. In those four studies you use for your assumption what are the established accuracy rates? 2. Furedy and Honts have been debating this for years and it should be once again noted that Furedy reserves ill comments for CQT not polygraph because he is a GKT format supporter. 3. Can you tell me what sensitvity and specifity has been established for any given forensic science by peer-reviewed and published studies under field conditions? 4. I don't think you read what I wrote in regards to the study. Iacono and Lykken obviously slanted the information given to the surveyed in the study. The study also lacks proper information for uninformed persons to be able to make a scientific analysis of the CQT. |
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Title: Re: The Scientific Validity of Polygraph Post by George W. Maschke on Apr 15th, 2002 at 2:14pm
J.B.,
Quote:
The accuracy rates obtained (not established) in the four studies are presented in a table provided at p. 134 of the 2nd ed. of Lykken's A Tremor in the Blood. I'll reproduce that table here for the benefit of those without ready access to the book: Table 8.2. Summary of Studies of Lie Test Validity That Were Published in Scientific Journals and That Used Confessions to Establish Ground Truth
As Lykken notes at p. 135, none of these studies are definitive, and reliance on polygraph-induced confessions as criteria of ground truth results in overestimation of CQT accuracy, especially in detecting guilty subjects, to an unknown extent. Do you mean to suggest that these four studies are adequate for determining the sensitivity and specificity of CQT polygraphy? Quote:
So what? This doesn't support your laughably implausible assertion that "[t]he reason CQT polygraph has not been unanimously accepted as a scientific method has nothing to do with its current accuracy rate or its scientific basis. It has to do with the squabbling between ideological camps as to who's question format is better." Quote:
No, not off the top of my head. I would assume that most diagnostic tests would be validated with laboratory studies. This is not feasible with CQT polygraphy because fear of consequences is a significant variable that is generally absent in the laboratory setting. What is your point? Do you mean to suggest that I'm holding CQT polygraphy to an unfairly high standard? Quote:
I read it, but frankly, I think you're "picking fly shit out of pepper" in an attempt to dismiss the results of a peer-reviewed survey that happen not to support your wishes regarding the scientific community's acceptance of CQT polygraphy. Again, you'll find the information provided to those surveyed cited (it's paraphrased in the journal article) at pp. 179-181 of A Tremor in the Blood. The description of the probable-lie CQT is largely cited from Raskin, a leading CQT proponent. Given the survey's high response rate, it would appear that most of those surveyed disagreed with your view that the information provided was inadequate for them to render an opinion on whether the CQT is based on scientifically sound principles or theory. |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Apr 16th, 2002 at 11:02pm
George,
You wrote: Quote:
If you take the more recent of these studies, those conducted in the 1990’s, the ‘obtained’ accuracy is much higher. Patrick & Iacono (1991) Honts (1996) Mean Guilty correctly classified 48/49 7/7 55/56 98% 100% 99% Innocent correctly classified 11/20 5/5 16/25 55% 100% 77.5% Mean of above 77% 100% 88.25% Confession based criteria is a dependable means of establishing ground truth if the definition of confession is well defined, adhered to, and the examiners’ decision based on the polygraph is pre-confession. As I have said before, one can not place a definitive base rate to sensitivity and specificity in a field setting due to the variable truthful and deceptive that may be present at any given time. Likewise, in any forensic science the base rate of these two areas is ever changing within the field based on the casework. Sensitivity and specificity are established in a controlled laboratory research environment. You have said chance accuracy and based your assumption on the four studies that you posted. I do not see where in any of these studies or even the four studies combined for a mean accuracy rate produce a not better then chance outcome in any of the areas. Even the lowest of the percentages is above chance. Quote:
Nonsense, the studies conducted by Honts had a much different reported outcome. So, Lykken and Iacono decided to do their own study to refute Honts et al. These studies where designed to find if general acceptance existed. General acceptance was an important element to establish because it was a main criterion for admissibility in court prior to Daubert v. Merrell Dow Pharmaceuticals. The rules of evidence have since changed post Daubert, see: http://cyber.law.harvard.edu/daubert/ch3.htm for the new acceptance criteria. I am not dismissing the results of any survey or saying the percentages are not what was reported. I am saying that this survey, as any, is only in part as good as the information provided, questions posed, and the how it is presented. It is my opinion that Lykken and Iacono’s survey was a poor attempt to discredit the acceptance of CQT, especially with the difference in the highly informed opinion. I do not think this is a good method of developing scientific acceptance for either format. GKT was reported as having 2/3 acceptance. However, can the difference in the two formats acceptance level be correlated to the presentation of the formats, the difference in amount of directed literature provided for each, and the degree of knowledge present in the surveyed for a given method? The survey does not pose equal questions across the board and leaves much to be answered. Just because Raskin is a leading expert in the CQT does not mean the majority of the surveyed who were relatively uninformed will give weight to his statements. Scientists are analytical in nature. (i.e.. tell me what is being done, how it was done, the results obtained, and how you calculated the results) If this previous information was properly presented in a scientific forum to the relevant societies and the same results were obtained, I would accept the results. This is not the case though. With the difference in the highly informed opinion, I think the results would be dramatically different to the positive. You wrote: Quote:
Laboratory studies can be useful in this area. See a conclusion on this topic at: http://www.polygraph.org/research.htm Quote:
Also, psychopaths’ and/or sociopaths’ have not been proven to be able to pass a polygraph when being deceptive. See: http://www.polygraph.org/research.htm Quote:
Quote:
It is not about ‘fair’ standards. It is about a consistent standard applied to other scientific or forensic scientific procedures for acceptability as being valid. Quote:
Again, the respondents based their survey-based opinion on the information they were given. Although paraphrased, the information is not consistent with that which is presented in a scientific forum for the review of a method for scientific validity. A conclusion that may be drawn from this survey is that the majority of scientists are not properly informed. |
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Title: Re: The Scientific Validity of Polygraph Post by George W. Maschke on Apr 17th, 2002 at 12:31pm
J.B.,
The two studies you point to do not establish that CQT polygraphy works better than chance, nor can any sensitivity and specificity for the procedure be inferred from them. The matter of sampling bias introduced when confessions are used as criteria for ground truth is indeed significant. You wrote: Quote:
But Lykken (A Tremor in the Blood, 2nd ed., pp. 70-71) explains how reliance on confessions as criteria for ground truth biases the sampling: Quote:
As Lykken notes (p. 134), in Patrick & Iacono's study, only one of the 49 guilty subjects could be confirmed as guilty independently of a CQT-induced confession, and his charts were classified as inconclusive. With regard to Honts' 1996 study, it would be appropriate to cite here Lykken's cogent commentary (pp. 134-35): Quote:
You also wrote: Quote:
Can sensitivity and specificity genuinely be determined for a procedure like CQT polygraphy that is both unspecifiable and lacking in control? In the message thread, What's more effective than the polygraph? you wrote: Quote:
Are you prepared, at long last, to reveal to us to whom that sensitivity and specificity is known, and what precisely it is? And what peer-reviewd research established it? Again, the sensitivity and specificity of CQT polygraphy appears to be unknown to the U.S. Government, and as Gordon Barland, formerly of the DoDPI research division, wrote in that message thread, "...I know of no official government statistic regarding sensitivity and specificity." You also wrote: Quote:
Again, J.B., my argument is not that CQT polygraphy has been proven by peer-reviewed research to have "chance accuracy," but rather that it has not been proven by peer-reviewed research to be more accurate than chance. There is a significant distinction between the two that still seems to elude you, but I'm not sure how to make the distinction any clearer. No accuracy rate (sensitivity or specificity) can be determined for CQT polygraphy based on the available peer-reviewed field research. Finally, with regard to Iacono & Lykken's survey of scientific opinion on the polygraph, however inadequate you may think the information provided to respondents was, the fact remains that the great majority of survey respondents believed they had enough information to render an opinion on whether the CQT is based on scientifically sound psychological principles or theory. And only 36% of Society for Psychophysiological Research members and 30% of Division One fellows of the American Psychological Association thought it was. If you genuinely believe that "[t]he reason CQT polygraph has not been unanimously accepted as a scientific method has nothing to do with its current accuracy rate or its scientific basis" and is instead attributable to "squabbling between ideological camps as to who's question format is better," well, more power to you, J.B. It appears to be a waste of my time and intellect to attempt to disabuse you of what seems to be a cherished delusion. |
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Title: Re: The Scientific Validity of Polygraph Post by akuma264666 on Apr 20th, 2002 at 12:02pm
I did not lie about my drug use, i have never used them. I did not lie about selling drugs, i have never sold them. I am not nor have I ever been a member of a group whose purpose was the destruction of my country. I have never been contacted by a member of a non- U.S. government for the express purposes of selling secrets. I am most certainly not a traitor to my country and yet your beloved polygraph has branded me so. My life has been ruined by that infernal machine and for you to maintain that the polygraph has an acceptable accuracy rate makes me very angry. For my position I don't care if the damned thing is 99% accurate, which it is not, it was wrong when it labelled me a drug selling, dope using, traitor and if it screwed me I can only imagine how many countless others it has harmed. The polygraph can not and should not take the place of old fashioned investigative work, it has no place in the preemployment process of the federal government.
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Apr 21st, 2002 at 5:50am
George,
You wrote: Quote:
The accuracy of any given method is established by the ?obtained? accuracy results. If a study is accepted though peer-review, then inferences can be made about the accuracy of the method by those results. The bias you speak of is directly dependent on the number of cases that where discriminated against because they lacked the criterion to be included. You wrote: Quote:
You once again assert Lykken?s opinion. What is Raskin?s opinion, whom you have admitted as a leading expert in CQT, on this study. It appears to be additional evidence of conflicting opinion between two separate ideologies on question methodology. You might ask why Lykken would refute Patrick & Iacono?s study when they are from the same ideological camp? Because the results turned out in the positive for the CQT. "CQT-induced confession", now that is ludicrous. Is Lykken suggesting that someone confesses because of the polygraph test question format used? It would be interesting to see this assertion supported through research. You wrote: Quote:
For one to say that a scientific method is unspecified, they must have definitive evidence of what other samples will produce the same results as the primary specificity. An example of this would be the Marquis test when used to identify heroin. In this test there are at least 50 other compounds that would produce the same result as the specified. In knowing what the specificity is, do you know of any other physiological response that would produce the same result during and after the asking and answering of a specific question? I know you will probably attempt to assert countermeasures. Countermeasures are not a physiological response but an attempt by one to produce a similar looking response to alter the test outcome to the positive. You wrote: Quote:
The answer to this that it is known in a controlled laboratory setting for research purposes, just like any other scientific method is established. You are asking for produced statistics that are not of the criteria used in the establishment of a scientific method. Gordon did not say that the specificity and sensitivity were not known. He said they were not known in the context that you had given, within the field. I have repeatedly answered this question to the point of your fixed inquiry and you have acknowledged that specificity and sensitivity are not obtained in the setting you wish to place them. You wrote: Quote:
Again, accuracy is set by the accepted results that have been obtained. Regardless of how it is worded (I fully understand the difference between has been and has not been), when something has not been proven statistically better then a given percentage then it has been proven to be equal to or less then the specified percentage. Knowing this, I have seen an abundance of accuracy rates that have obtained above chance accuracy rates, including the peer-reviewed field research you recently posted as support for your assertion, but not one that supports "has not been proven by peer-reviewed research to be more accurate then chance. You wrote: Quote:
This is a redundant argument that we should just agree to disagree on. This is simply a survey and has nothing to do with the scientific validity or, as I previously pointed out, the currently established rules of evidence. You wrote: Quote:
I agree this to be a moot point. However, there are no delusions on my part. |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Apr 21st, 2002 at 6:12am jrjr2 wrote on Apr 20th, 2002 at 12:02pm:
akuma264666 , I have never advocated the use of polygraph in a pre-employment screening process the way it is currently used. There is little scientific research in the use of polygraph for this purpose and none that is favorable, in my opinion. I agree that nothing can nor should replace a thorough background investigation. My argument for polygraph, as are all my arguments for polygraph, being scientifically valid is in a specific criminal issue testing. This use is were the majority of scientific research is done and where polygraph has been shown to have high validity. |
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Title: Re: The Scientific Validity of Polygraph Post by George W. Maschke on Apr 21st, 2002 at 10:50am
J.B.,
You wrote: Quote:
I'm not sure what your point is. Are you arguing that sampling bias is not a significant factor in the peer-reviewed field validity studies by Patrick & Iacono and Honts? Quote:
No, J.B., I did not "once again assert Lykken's opinion." I referred to an inconvenient (for polygraph proponents) fact that Lykken has pointed out: "in Patrick & Iacono's study, only one of the 49 guilty subjects could be confirmed as guilty independently of a CQT-induced confession, and his charts were classified as inconclusive." Your suggestion that Lykken's discussion of Patrick & Iacono's study amounts to a refutation of it is evidence that you haven't read Patrick & Iacono's study. If you had, you would know that Lykken's observations on the matter of sampling bias are entirely consistent with the conclusions drawn by Patrick & Iacono, which are implicit in the title of their article, "Validity of the control question polygraph test: The problem of sampling bias." (Journal of Applied Psychology, 76, 229-238) In response to my following remarks: Quote:
you replied: Quote:
Your reasoning that "when something has not been proven statistically better then [sic] a given percentage then it has been proven to be equal to or less then [sic] the specified percentage" is a logical fallacy of the argument to ignorance (argumentum ad ignorantiam) variety. That something has not been proven to work better than chance does not mean that it has been proven to work no better than chance. If you cannot grasp this elementary concept, then my further debating with you the topics you proposed to discuss when you started this message thread is pointless, really. |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Apr 23rd, 2002 at 7:31am
George,
The first response (highlighted to show emphasis of the point) I gave in my last post; Quote:
If the sampling bias was so significant, I would think the research would not have been accepted for publishing after peer-review. Lykken et al have criticized the use of a confession based criterion in the past. However, it appears it was still used in the Iacono & Patrick study, minus the one case. In the real world, it is difficult to establish this criteria. Again, I don't feel that this is the best method but is an acceptible method if it follows strict guidelines such as the ones I posted prior. You wrote: Quote:
I don't see this as an 'inconvenient (for polygraph proponents)'. How do you propose it is? You wrote: Quote:
I never once indicated that Lykken's view differed from that of Patrick & Iacono. You have a right to your opinion. Again, they have refuted sampling bias based on this criterion previously but still sought in using it for their study. If it is such a bad method, then why did they not use a different method? I can't help but wonder what the comments or lack there of may have been if the 'obtained' accuracy results would have been less favorable. You replied to my previous post about statistical accuracy: Quote:
This is not a 'logical fallacy'-"The argument to ignorance is a logical fallacy of irrelevance occurring when one claims that something is true only because it hasn't been proved false, or that something is false only because it has not been proved true." It is a 'contradictory claim'- "A claim is proved true if its contradictory is proved false, and vice-versa." I am saying that there is proof, found in the four studies you illustrated as support for your statement, that polygraph has been proven to work better then chance in peer-reviewed field research. By definition of this argument, my claim has been proven true and unless you can provide refuting evidence that your assertion is true then yours is false. If you could provide contrary evidence to support your assertion, then my claim would be a 'contrary claim' and not a 'logical fallacy'. |
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Title: Re: The Scientific Validity of Polygraph Post by George W. Maschke on Apr 23rd, 2002 at 9:16am
J.B.,
You seem to pooh-pooh the matter of sampling bias when confessions are used as criteria for ground truth. However, I don't think there is any rational ground for ignoring it, as I've explained above in my post of 17 April. It's significant with regard to what conclusions may be reasonably drawn based on the data obtained in the studies. With regard to Patrick & Iacono's article, you write, "I never once indicated that Lykken's view differed from that of Patrick & Iacono." Sure you did: in your post of 20 April when you wrote, "You might ask why Lykken would refute Patrick & Iacono's study when they are from the same ideological camp?" You insist that your assertion that "when something has not been proven statistically better then [sic] a given percentage then it has been proven to be equal to or less then [sic] the specified percentage" is not a logical fallacy. I don't have the patience to take you through this step-by-step, but I suggest that you carefully consider what you wrote (which is perhaps not what you really meant). Finally, you suggest that the four peer-reviewed field studies cited in Lykken's A Tremor in the Blood show "that polygraph has been proven to work better then [sic] chance in peer-reviewed field research." Your argument seems to be essentially an argument to authority (argumentum ad verecundiam), suggesting that the results obtained in these four studies must prove CQT validity works better than chance because the articles were published in peer-reviewed journals and the accuracy rates obtained in them exceeded 50%. For numerous reasons that we've discussed above, I disagree with this conclusion. Again, as Lykken notes at p. 135, none of these studies are definitive, and reliance on polygraph-induced confessions as criteria of ground truth results in overestimation of CQT accuracy, especially in detecting guilty subjects, to an unknown extent. In addition, chance is not necessarily 50-50. Moreover, as Dr. Richardson eloquently explained, CQT polygraphy is completely lacking in any scientific control whatsoever, and as Professor Furedy has explained, it is also unspecifiable and is not a genuine "test." Lacking both standardization and control, CQT polygraphy can have no meaningful accuracy rate and no predictive validity. |
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Title: Re: The Scientific Validity of Polygraph Post by J.B. McCloughan on Apr 26th, 2002 at 6:41am
George,
You wrote: Quote:
For you and/or anyone else to say that the sampling bias is and/or was significant, the estimated number of cases/samples excluded would need to be established. Although this measurement is nearly impossible in some applications, as an example large census polls, it is able to be established in this particular research method. However, the problem you purpose is not a sampling bias per se but a potential measurement bias. From: http://personalpages.geneseo.edu/~socl212/biaserror.html Quote:
Here is a more definitive explanation of criterion sampling. From: http://trochim.human.cornell.edu/tutorial/mugo/tutorial.htm Quote:
You wrote: Quote:
If you would have placed my entire explanation of this, one can plainly see I didn't say that Lykken's 'view differed' from that of Pratrick & Iacono. I wrote: Quote:
Lykken refuted the high validity results obtained by the study. This has nothing to do with Patrick's and/or Iacono's views on the CQT question method or that Patrick and/or Iacono did not refute the validity results obtained. This is a percentage obtained from the collected and processed data of the research study. You wrote: Quote:
An example of a 'logical fallacy' would be if you would had stated that polygraph has never been proven to work so it does not and I countered with it has never been proven to not work so it does. One of your errors in using this word is in that you have placed a statistical percentage 'chance' to your assertion, which makes it definitive and not speculative. Even if your definitive suggestion were subjected to this definition of 'logical fallacy' with the percentage included, my assertion still does not meet the definition of a 'logical fallacy'. I would have had to state that when something has not been proven statistically better then a given percentage, then it has been proven to be equal to or (greater) then the specified percentage. Furthermore, there would need to be an established general knowledge that neither has been proven true. I have already explained this error to you and provided you with the full definition of a 'logical fallacy' and the true definition of this argument ?contradictory claim? from the source that you used. Again, you attempt to play on words by segmenting statements I have made. I fully understand the definition and have taken the time to explain it to you. I followed this statement with explanations and the conflicting data to your assertion that supports my assertion of being proven to work at above chance in peer-reviewed field research. I wrote in support of the assertion: Quote:
You wrote: Quote:
You are correct that my assertion is that these four studies provide proof of above chance validity. You are asserting a conflicting view, which you have the right to, that has no support for its assertion and thus is just a lay opinion. Again, by definition of 'contradicting claim' my assertion is true because it has been proven and thus your view has been proven false because it has not been proven. My assertion is not an 'argument to authority (argumentum ad verecundiam)'. The data speaks for itself and has been accepted. Just because Lykken et al refute the obtained accuracy results, does not mean that the results were not accepted. Your assertion on the results being unacceptable is the fallacy of Ad Verecundiam, since Lykken et al present a biased towards one side. From: http://gncurtis.home.texas.net/authorit.html Quote:
You say you disagree with the statistical data of the four field research studies but you used them as a support for your assertion. I will reiterate, this is not a sampling bias per se by definition. Again, any bias that may or may not have been created was due to criterion selection (measurement bias). Anyone can say that something caused error. However, in the statistical realm one must provide reason and deduction from the data that supports the view for it to be a valid assertion. More importantly, for one to assert that the statistical data contains criterion/measurement based bias, there would need to be an attributing result to an external and/or internal variable in relationship to the criterion. The fact that the confession criterion was used does not in itself create a per se bias. Here is a hypothetical instance of how a confession based criterion research study may produce a criterion/measurement bias; Confession was used as the criterion for the selection of deceptive polygraph chart data because it is a means of confirming the results. In conducting the study, it was found that the original polygraph examiners' decisions were made after the post-test interview and based on the confessions obtained. Since the original decision and the selection criterion were the same, one can not separate this variable from the original examiners' decision and/or use another sources independent of the confession to base the original examiners' decisions on the polygraph chart data. The criterion based selection method thus caused an unknown degree of bias in the accuracy rate obtained from the deceptive cases reviewed. I agree that chance is not always 50/50. If the accuracy results obtained for deceptive based on the original examiners' decisions have only the two possible outcomes of a correct or an incorrect original decision, the original decision had a 50 percent chance of producing either result. If you can point to another decision available and/or the reason that 50/50 is not the chance level of these studies, I would be willing to discuss that. I respect Drew's views as a scientist but disagree with him on the issue of the scientific definitions we debated. My definitions are from other accepted scientific disciplines manuals. These manuals and their contents are nationally reviewed and accredited. I feel the correlation of the presented structures within CQT polygraph meet these definitions and Drew does not. I agree to disagree with him on this issue. |
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