Will my simple lie detector work ?

Question

Its based on measuring resistance of skin .... the skin resistance goes down due to increase in moisture when one sweats while lying. But its not going to work for false or non-serious lies. Will it work when, say, we wet the skin using water or something ??? I'm only doing this for a high school project ... so that much will be enough.

Answer 1

You'd find that you would have more success with one that would be able to measure pulse from certain parts of the body. When someone lies, their pulse changes. A slower more consistant hearbeat/pulse shows a truthful answer, where if the heartbeat.pulse speeds up or become irratic, it shows a false answer.

Answer 2

Polygraph, any of various scientific recording devices designed to register a person's bodily responses to being questioned. Popularly known as a lie detector, the polygraph has been used chiefly in criminal investigations, although it is also used in employment and security screening practices. Because no machine can unerringly recognize when a person is lying, the polygraph results are used in conjunction with other evidence, observations, and information. Emotional stress reflected by this test, for instance, need not be due to lying. On the other hand, a subject may be a pathological liar and therefore show no measurable bodily responses when giving false answers. Ordinary nervousness, individual physical or mental abnormalities, discomfort, excessive pretest interrogation, or indifference to a question also affect test accuracy. The polygraph can, however, provide a basis for an evaluation of whether or not the subject's answers are truthful. This test has also been helpful in exonerating innocent persons accused of crimes.

A polygraph is actually several instruments combined to simultaneously record changes in blood pressure, pulse, and respiration. The electrical conductivity of the skin's surface can also be measured—increased sweat-gland activity reduces the skin's ability to carry electrical current. The Reid polygraph, devised in 1945 by the American criminologist John Edward Reid, also records muscular movement.

Apparatus worn by the seated subject includes a so-called pneumograph tube around the chest, an ordinary blood-pressure cuff, and electrodes on the fingers and surfaces of the hand. The actual physiological changes are transmitted, through a small panel unit, into synchronized readings on moving graph paper; these parallel graphs are then correlated and interpreted to determine whether the subject is lying.

Proper conditions and procedure are essential in polygraph testing. The room used should be plain, quiet, comfortable, and private; two-way mirrors and microphones are sometimes used as legal precautions. The examiner's role is also important. He must be consistently objective and should be thoroughly trained in scientific interrogation to reduce the inherent human error.

Polygraph results are generally considered inadmissible as legal evidence in U.S. courts, except where mutual agreement is given by the opposing parties in a case, and the use of the device in private employment procedures was severely restricted by federal law in 1988. The chief objections to the polygraph are that its use is unconstitutional, that it constitutes an invasion of privacy, and that it is still too inconclusive scientifically to be considered valid as evidence. In several countries the use of the polygraph is prohibited by their governments on the basis of violation of free will.

visual browser



related articles


Crime Detection
Evidence
Invasion of Privacy
inventor of original polygraph
physical processes measured
use in employee screening for the FBI
8 items
multimedia




1 item
web center
Ä Find the best online information about Polygraph.
Encarta Editors' Picks
Crime Detection [FBI Kids & Youth Educational Page]
more...

go through this..so that u can improve ur project

Answer 3

Basing a lie detector on the resistance of skin is fallible. You best bet is to test a person's heart rate. If your set to use your lie detector as it is, then the water will set the detector off.

Answer 4

Why don't you try it out? There is nothing like empirical evidence to settle a question like this.

I doubt it will be very sensitive.

Answer 5

No.. it will NOT work

Answer 6

I just dont think it will work.

Answer 7

try the pulse....

Answer 8

LIAR