TV reality show polygraph tests: the reason some are more accurate than others

TV reality show polygraph tests-- the reason some are more accurate than others:

Because sometimes a TV polygraph is known as a 'Two-thirds test'.

Time is very limited on a film set;

On a thorough polygraph exam, instead of simply just scoring pass or fail at the end, during the final third of the test sometimes a polygraph examiner might want to 'dig deeper' on an answer that indicated deception. This end portion of the testing is known as the 'Post-Test'. This attempt to either verify the 'fail' or to determine if there was a non-lying outside cause for the fail (something other than lying), an examiner might mention that an answer was showing deception and then modify the question or use interview methods to finish the matter.

But on some TV shows, examiners are instructed to keep the fail unmentioned to the examinee and to NOT dig deeper; it is left for the show host to do the 'digging'.

Example: a wife suspects that her husband secretly has been engaging in homosexual situations. During the polygraph exam the husband shows deception when denying it. Usually, such results indicate that he was lying. BUT, sometimes, had the examiner been allowed to tell the examinee of the results, gentle further probing has been known to bring the admission such as a rape by a family member when a youth. Then, the question might be modified to "Other than what you just told me about, have you ever . . . ".

Such an admission is far more likely to occur when the examinee is one-on-one with an examiner than in front of a filming audience.

Secret: some 'TV polygraphers' pass almost everyone, simply because they don't want any dispute.