So it's the word "composure" that's throwing you guys off.  I'll let the team at the Arkansas Polygraph Association summarise a particular case for us:

"In the case, US v. Scheffer, it was ruled by the Supreme Court that polygraph evidence dint [sic] not have to be admitted in military court as evidence as the military were trained enough in keep[ing] their composure and could cheat polygraphs with their calm demeanor."

The link is: arkansaspolygraphassociation(dot)com/officers

As a funny side note, the accused was trying to use the polygraph results in his favour.   

Aimes, a successful polygraph foiler, posited: "...go into the test rested and relaxed.... try to maintain your calm."


While "composure" is a state of mind representing calm.  The result of a calm body can be measured.  Pulse, blood pressure and breathing all occur within a normal range.  When your body is stressed, your pulse increases, blood pressure increases and breathing rate increases.  And if your body is stressed, your mind is stressed.


Now, each person's baseline is slightly different.  If you are composed, meaning you are RELAXED and CALM, your body will not indicate an increase in the aforementioned items.   


All of this information can be found in the book on this site.


Stefano/quickfix,

Arkansas Polygraph Association's page:

"Polygraph machines are made using a combination of medical devices that monitor any change occurring in the body."

California Forensics:

"The polygraph instrument is basically a combination of medical devices that are used to monitor changes occurring within the examinee’s body."


Bill Brown,

Let me ask you two questions because you're obviously the person with the most experience here:

1) When a person's mental state changes from calm to stressed, are there physiological indications of such changes?

2) If physiological changes occur, is the polygraph able to record those changes?

Sorry for the duplicate.

Stefano,

Pull your pseudo-intellectual head out of your bum and enlighten me.  Why is it that you can never write anything substantial?  You seem to have a knack for writing sentences that are broad and contribute nothing.

Now, if you'll be so kind as to tell me why the APA and Ames were incorrect, using that big noggin of yours that you pretend is so full yet has failed to produce ANY data, sites with data or even anecdotes.

Of course, you can always just stop writing back.  It would certainly be your best argument so far because then I'd at least know that you have some level of reading comprehension.

Stefano,

That's what I thought. 

Let me leave you with some final words to chew on.  Your only experience with the polygraph is the one time you failed it.  You're incapable of articulating your thoughts (if you even have any), you're incapable of critical thinking and you're a failure.  It's no wonder the government rejected you.

Toodles,

GS

Quote:

This seems to assume that false positives consist of a false accusation of deception by the polygraph operator, followed by a loss of composure by the examinee.

That is not how my false positives went.  Do you have any data to show what percentage of false positives occur that way?


And, BTW, this seems more like rationalization than anything else.  The polygraph is not touted as a way to measure someone's composure under stressful conditions - it is purported to be a scientifically valid method of detecting deception.  If it is unable to do that accurately, as in the case of a false positive, the polygraph and its operator have utterly failed in their mission.  To try and claim that they have succeeded in some tangential fashion by showing that the examinee loses composure under stress is disingenuous at best.

Quote:

Duck,

You hit the nail on the head.

An officer I met at an instructor development class is a tactical officer in a large city.  He does lots of search warrants on drug houses - what is often called "tumultuous entry."  In other words, he is in the stack outside the door when they yell "Police! Search warrant!" and smash the door open with a battering ram.  He has probably had more guns pointed at his face than I have seen in my lifetime.  His coworkers all describe him as being utterly cool and composed during every raid, even when taking fire or having someone rush him with a knife or a baseball bat.

In this class, we all had to develop a lesson plan and teach ten minutes of it in front of everyone else.  I thought this guy was going to have a heart attack.  He was beet-red in the face, was nearly hyperventilating, and he could barely remember the title of his presentation.  He was literally terrified of getting up in front of a group and speaking.  And the group he was teaching was all other cops he knew at least to some degree.

If someone going through the arduous and tedious police application process is wrongly accused of some crime that will derail their chances of ever becoming a cop, it is entirely normal if they show stress.  Sometimes a great deal of stress.  The fact that they do is entirely unrelated to how they will or will not function under stress on the job.