How Accurate is the Polygraph Test?
There are now about 25 research studies available on the accuracy of the polygraph tests. In ‘real life’ cases, researchers have found it very difficult to assess the accuracy of polygraph examination because the ‘ground truth’ criteria are often lacking i.e. it is not possible to find a representative sample with which one can establish with certainty who is and is not actually telling the truth. Based on the studies now available, experts assess the accuracy of polygraph examinations administered by a competent examiner to be about 90%. Level of skill and experience of the examiner plays an important part in the accuracy of the examination. Comparative studies have shown that polygraph tests yield an accuracy that equals or exceeds that of many other forms of evidence. In one study, it was shown that polygraph tests produced an accuracy that was comparable to results obtained by document examiners and fingerprint analysts, and exceeded that of eyewitnesses. The polygraph test is ofte
Recent research reveals that the accuracy of the new computerised polygraph system is close to 100 percent. In the past 75 years, over 250 studies have been conducted on the validity, accuracy and reliability of polygraph testing (American Polygraph Association 1996 Polygraph Issues & Answers). Based on twelve separate studies involving 2174 real cases since 1980, evidence suggests that qualified polygraph examiners are 98 percent accurate in their overall decisions (Norman Ansley, “The validity and reliability of polygraph decisions in real cases”, Polygraph, v.19, 1990). Research clearly indicates that when administered by a competent polygraph examiner, the polygraph test is the most accurate means available to determine truth and deception.
