raymond.nelson wrote on Jan 15^th, 2008 at 5:16pm:

nopolycop wrote on Jan 15th, 2008 at 3:50pm: Both of these analogies require an active response though by the testee, and neither purport to read a person's thoughts.  The polygraph purports to be able to tell what a person is thinking, and doesn't require an active response.  Apples and oranges. That is absurd. Polygraph testing is about stimulus and response, just like so many countless other tests. Nobody, except perhaps yourself and Mr. Maschke, has suggested the polygraph can read minds. nope'cop, you are overstepping the bounds of your expertise here, and  engaging in a silly straw-man argument. It would be much more informative to yourself, and the other readers, if you would constrain your discussion of polygraph to an actual conversation about testing theory or item response theory. Unless for some reason you are not interested in an authentic discussion of the matter. r

Correct me if I am wrong, but a poly exam is supposed to be able to tell if a person is lying or telling the truth correct?  

Assuming that is correct then, and the the obvious fact that unless a fact is confirmed by outside evidence, (such as the DNA evidence that Gary Ridgway left with  his victims after his "passed" polygraph) there is no real way to confirm if the polygraph results are in fact correct.  Even a confession by a testee, while likely to be accurate, really cannot be confirmed except by independant means.

Thus, unless a fact is confirmed by independant means, then one trusts the opinion of the polygrapher as to what the person is thinking after the question is asked, as it is what he is thinking that causes the physiological response such as increased breathing rate, increased sweating, higher pulse rate and increased blood pressure.

I am not naive as to what occurs in a polygraph exam, I have taken three of them in my lifetime.