posted 02-02-2006 05:51 PM            

I'm not sure there is a correct answer to the question I presented. I believe we will conduct the exam dictated by our experience, circumstances and issue under investigation to obtain the best results. A

As previously stated, my first choice if I have a chance to run an exam of a suspect is the CQT. An NDI in either the CIT/CKT or GKT could be due to "psychological set." The condition in which an examinee responds to a question that is most threatening to their well-being.

The examinee may not care in the least if we learn (they) appear to know a knife or gun was used in a murder. Maybe care even less if we suspect (due to a CIT/CKT or GKT)the examinee knows some other evidence connecting information. Since they are not concerned too much with this information they may run NDI.

They may be more concerned (psychological set) with a "did you cause the death of question" & for this reason may run NDI on other issues.

There can always be exceptions & extremes.

I've (heard) of a homicide case in which an MGQT was administered. The examinee did not have any problems with the "did you cause the death of" question (Q-5) but did show DI to the question: "Right now, can you take me to the weapon used to cause the death of" question (Q-9).

In this specific case I will guess running any of the "knowledge" tests (first) may return NDI.

The examinee subsequently confessed. In this case the examinee reportedly stated they were most worried about the gun used as they knew where it was concealed (they concealed it). In addition, they were concerned about a ballistics match & fingerprints as they thought it was in a secure location and had not been cleaned. The examinee reported they knew their weapon (gun) was a direct link to the murder.

posted 02-02-2006 09:52 PM            

An examinee denies involvement in a crime (CQT) and denies knowledge of a known fact pertaining to the crime (CIT). No matter what "brain function" is involved psychological set may very well be the reason they are NDI in the CIT and DI in the CQT. Does current research support discounting psychological set as it pertains to polygraph? If true, what is the reason cited that there may be a response in a CQT & not in a CIT?

I don't give away any information to run a CQT. Our responsibility is to learn what the examinee knows, not provide them with information about a crime. To the extent that it's already been shown CIT results should be viewed with caution, I believe this is more reason to get information & not release any.

posted 02-03-2006 08:47 AM            

The CIT is well grounded in science, and the whys are a lot easier to explain. If I remember correctly, Ben-Shakkar (spelling?) et al discussed it in some detail in their chapter in Kleiner. Lykken also discussed it in Tremor in the Blood. There are a number of studies out there as well. (Now, I'm not saying the whys are all set in stone, but there's considerably less debate - and on fewer issues.)

If you choose to educate yourself on the topic, it might be overwhelming at first as it necessarily requires a study of brain physiology, human memory, and a host of other psychological topics. It's not an easy question to answer, and I wouldn't attempt it here. In my opinion, oversimplifying it here would do a disservice to those only reading this limited info. I would encourage you to read more on it, but keep in mind, most of the writers loathe the CQT (as do those in the article you were quoting from in the former topic / thread).

In a CIT there is one relevant (or critical item) and four (real) controls. We aren't really comparing question types as you don't have to ask any questions to run a CIT. We simply identify the single most salient item, and there's little subjectivity in that. A person need not fear a thing to consistently react to the critical item.

posted 02-03-2006 01:07 PM            

Psychological Set. Nobody knows why this occurs, 14 different theories (why), no definitive answer. As a result, this old term apparently remains the reason why we may find DI in one exam and NDI in another exam related to the same issue!

If the CIT is "well grounded in science" as you state, does the APA sanction its use to detect criminal guilt (like the Japanese)? Have I missed something while I was away?

END.....

posted 02-03-2006 01:29 PM            

The Guilty Knowledge Test name change, in my opinion, was to avoid problems that may arise in explaining ones results. It may vary well change names again to something like the Information Recognition Test (IRT), Correct Answer Recognition Test (CART), Hidden Event Recognition Test (HERT), Hidden Answer Recognition Test (HART), Critical Event Recognition Test (CERT), or some other recognition based title, as these are true to the analysis being conducted with the test. The name can vary but in general terms it should be descriptive as to what you are measuring for.

When it comes to a “valid” test, there are two major validity measurements of a test for scientific and evidentiary purposes.

The first and foremost is construct validity. If you do not have construct validity, scientifically your results will matter not because you cannot explain what they mean. Construct validity deals with the issue of a theory being scientifically sound. It involves repetitive tests of that theory with like results, reliability. First the theory must be tested to show that what is said to be measured for is. Then any other explanations for it occurrence or alternative theories/hypothesis must be disproved (e.g. orienting response vs defense response).

The second validity issue is criterion. Criterion validity (accuracy) basically deals with the overall ability to identify and eliminate that which it is (sensitivity) and is not (specificity) looking for respectively. This is only a basic summation. There are other measurements of criterion validity and, if you are interested in this topic, those measurements can be readily accessed via a search on the internet. I would begin with the aforementioned terms.

The CIT has shown to posses both construct and criterion validity.

The CQT has shown to have criterion validity, it accurately identifies at or above what other acceptable behavioral science tests do, but it has not established construct validity (sound theory). In fact, some of the terminology we use to explain proposed polygraph theories is not accurate (e.g. psychological set).

As to some of the original questions posed by Poly761:

quote:

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As previously stated, my first choice if I have a chance to run an exam of a suspect is the CQT. An NDI in either the CIT/CKT or GKT could be due to "psychological set." The condition in which an examinee responds to a question that is most threatening to their well-being.

---

As stated earlier, “psychological set” is not at play in the behavioral science definition of the word. It is generally accepted that there is no emotion that is purely physiological and the reverse is true. Physiological responses may be chemically induced that mimic what an individual attributes to an emotion from life experiences. However, the chemically induced physiological response lacks the attached thoughts/memories. Emotional labels as we know them (e.g. anxiety and sadness) are based on individual psychosociological conditioning. Also, what is one persons fear is another persons fantasy.

quote:

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The examinee may not care in the least if we learn (they) appear to know a knife or gun was used in a murder. Maybe care even less if we suspect (due to a CIT/CKT or GKT)the examinee knows some other evidence connecting information. Since they are not concerned too much with this information they may run NDI.

---

This may be a factor in an interrogation but has nothing to do with a forensic examination. The same argument is true that a subject may not care that his/her DNA was identified from a sample taken from a crime scene. However the subjects concern on this issue is irrelevant to the jury at deliberation.

quote:

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I've (heard) of a homicide case in which an MGQT was administered. The examinee did not have any problems with the "did you cause the death of" question (Q-5) but did show DI to the question: "Right now, can you take me to the weapon used to cause the death of" question (Q-9).
In this specific case I will guess running any of the "knowledge" tests (first) may return NDI.

---

Maybe. However, if the item has significance to the individual (salience) then it would be fair to assume that it is memorable. If this were the case, the subject would most likely show his/her stronger orienting response to the correct item and show recognition of it out of the other plausible alternatives.

In summary, the CIT is a valid test and is accepted by the polygraph and academic community as such. The CIT using a scientifically accepted theory that has been tested with acceptable results identifies whether or not a subject recognizes the correct answer, which is thought to be concealed, over the other plausible alternatives. It does not infer "guilt" as originally its title suggested nor does the "Brain Fingerprint" find whether or not there are fingerprints on the brain.

posted 02-04-2006 02:19 AM            

Should we really worry much about any test "being descriptive" as to what we are measuring? I'm more concerned with the structure of an exam/test. The GKT can be changed to many names but the reason that it is conducted remains. We want to know if the examinee has specific information relative to an issue.

Since the CIT is accepted as a "valid test," but not a test used to determine criminal guilt, wouldn't it be best to use this test as a follow-up to a CQT? Relevant information need not be disclosed in the CQT that asks the "Did you" question. My issue with the GKT/CIT is, at best, we only learn the examinee (knows) relevant information regarding an issue. We don't learn how they gained knowledge of a relevant issue.

Wouldn't a DI to a CIT (after) a DI with a CQT (support) the CQT opinion?

Regarding (your) second quote of information I submitted. I commented an examinee may not care if we learned they appeared to know a knife or gun was used in a murder, etc. Since they weren't concerned this could be the reason for an NDI.

But, in quoting me, you did not include the next 3-lines I wrote that are relevant to the point I was making: I submitted the reason the examinee could be NDI was that they were more concerned with the "did you cause the death of" question. And, there can always be exceptions and extremes. How is it this information has "nothing to do with a forensic examination?"

I don't understand your comment that "a subject may not care that his/her DNA was identified from a sample taken from a crime scene. However the subjects concern on this issue is irrelevant to the jury at deliberation". If the subject denied being present at the crime scene I have no doubt the subject will be concerned their DNA was present at the scene.

It appears we're going full circle on this issue and back to a portion of the topic title. Which comes first? Which exam would you run first?

You state " - if the item has significance to the individual (salience) then it would be fair to assume that it is memorable. If this were the case, the subject would most likely show his/her stronger orienting response to the correct item and show recognition of it out of the other plausible alternativies."

I'm presuming you are referring to a CIT in the preceding paragraph. In a CQT, salience does not always relate to a "stronger orienting response."

END.....

[This message has been edited by Poly761 (edited 02-04-2006).]

posted 02-06-2006 11:31 AM            

As field examiners, you are correct that our worry is not so much in choosing the name of the exam but in the proper conductance of the examination. The name is for the most part rather unimportant but could be cause for further explanation in a court proceeding, as was the case that changed “controls” to “comparisons”. In this setting, the congruence and proper use of terminology is important.

Although sometimes implied in an investigative situation, I do not think that we can ascertain if an individual has specific information per se with the examination alone. We can only determine that they appear to recognize the correct answer based on the orienting response received and research that supports this.

In my response to you reference the homicide example, I was responding to your ideas as a whole. Your post had two separate ideas on what was more salient to the subject. In addition to the three lines I omitted, I also omitted the later quote about a MGQT where the subject was more concerned with the weapon’s location.

If the polygraph is to be used as an investigative tool, how we use the polygraph and its results has a broader range with fewer restrictions. If we use it as a forensic test for evidentiary purposes, there are greater restrictions. My comments about forensic examination and the subject's care for us discovering their knowledge via the examination(s) were not meant to be at you but at the issue of investigative tool vs. forensic examination.

The subject’s concern can be viewed to mean different things. In the way I was using it, concern was used in reference to how a specific event or item might be more memorable or recognizable to the subject. Whether they are emotionally concerned with it or not is inconsequential to the CIT but what is memorable is, as it is cognitive test.

Given the two different examinations strengths and weaknesses, I do think that you are correct that these examinations would benefit each other. If both properly conducted examinations agreed, it should reduce the probability of error to almost zero. Just because a subject does or does not recognize the correct answer does not imply that he/she did a crime. Again using DNA as an example, presence of evidence connecting someone to a crime or crime scene does not imply they are “guilty” of the crime, a trier of fact issue. However, it may assist the trier of fact to come to the conclusion of guilt or innocence when coupled with other competent evidence.

The issue of where to place the CIT can for the most part be one of personal preference, as long as you are not using the specific information to be tested in the CIT in the CQT.

You are correct that my reference to salience was in regards to the CIT. It may also be true with the CQT but we cannot infer that as there are no research studies that support any of the theories. We have failed to test the construct validity.

You have started a great topic and I enjoy thinking aloud here with you and the others. I do not think that your views are much different than mine and both of our ideas help answer pressing questions in the profession on this issue. Understand that I am mainly taking the evidentiary approach to polygraph and completely understand that there is an investigative side that is equally important.

posted 02-07-2006 02:24 AM            

I'm glad to have access to this site to learn how other examiners are thinking relative to various exam issues. Thanks for your time.

posted 02-08-2006 04:47 PM            

One part of this topic that deserves some discussion is the CKT's (there are probably better names, but this is the one I'm using today) structural ability to reduce the probability of error. By running additional tests on mulitple critical items you can mathmaticly reduce the false positive error probability.

For example, using a 2 pt. scoring system on your CKT where the most significant reaction is scored a "2", and the next most significant reaction is scored as "1"; if you were to run two CKT's on a homicide... say wound location and weapon used and the critical Items each scored a "2" on your charts you have a calculable false positive error of 4.0%. If you ran a 3rd CKT regarding victims shirt color and once again your critical item scored a "2" then your false probability error reduces to 0.8%. ( I didn't figure this myself guys this came off of the NPC cheat sheet) What detective wouldn't begin salivating if you could tell him you were better than 99% sure a particular suspect deserves special attention?

On CQT tests your probability of error is based on less objectively calculable criteria.

The main problem with CKT is that some investigators have a strong need to disclose how much they know about a case when dealing with suspects and witnesses.
Our protocol is to call the polygraph examiner to the scene of the crime to determine wich critical items need to be kept secret for polygraph.

The main advantage is that CKT can be used to screen large numbers of suspects in a comparitively short period of time.