can Lie Detector test be wrong?

Question

i'm wondering can they what thier percenage of being right.

Answer 1

The American Polygraph Association has a compendium of research studies available on the validity and reliability of polygraph testing. The 80 research projects listed, published since 1980, involved 6,380 polygraph examinations or sets of charts from examinations. Researchers conducted 12 studies of the validity of field examinations, following 2, 174 field examinations, providing an average accuracy of 98%. Researchers conducted 11 studies involving the reliability of independent analyses of 1,609 sets of charts from field examinations confirmed by independent evidence, providing an average accuracy of 92%. Researchers conducted 41 studies involving the accuracy of 1,787 laboratory simulations of polygraph examinations, producing an average accuracy of 80%. Researchers conducted 16 studies involving the reliability of independent analyses of 810 sets of charts from laboratory simulations producing an average accuracy of 81%. Tables list the authors and years of the research projects, which are identified fully in the References Cited. Surveys and novel methods of testing are also mentioned.

http://www.polygraph.org/betasite/apa5rev.htm

Answer 2

some people are good liars and can lie in front of a lie detector without it sensing it, while some people are just nervous by nature and would set off the lie detector even when telling the truth.

Answer 3

I learned in Law class that the lie detector cannot be used for evidence in the court because the results are not 100% right. Cause it basically reads how anxious you are.

Answer 4

A lie detector or polygraph is about 70%-90% accurate. There is also a new system using an MRI that is about 90% accurate:

http://www.usatoday.com/tech/science/2006-06-26-mri-lie_x.htm

Answer 5

yes, lie detectors can be wrong. People in the military have been trained to pass them. Lie detectors rely on your pulse and when you are nervous your pulse goes faster and that is when the lie detector thinks someone is lying.

Answer 6

Yes

Answer 7

yes they can it is VERY rare but you cant use them in court any more because they are flawed
they use you heart rate to tell if you are lying if the your pulse is going even the slightest bit faster the needle will wiggle around more but some people can beat it and others are nervous to tell

Answer 8

That's right

Answer 9

most of the time they are correct but yes they can be wrong that has happened time and time again

Answer 10

So glad that I found this topic already answered! Its like you read my thoughts!