How accurate is a polygraph?
The polygraph has been proven to be up to 98% accurate. Results from a polygraph will be Deception Indicated (DI), No Deception Indicated (NDI) or Inconclusive/no opinion (INC or NO). While most cases will be determined during the polygraph, sometimes an examination will be inconclusive. This means no opinion is rendered as to deception or truth.
Recent research reveals that the accuracy of the new computerized polygraph system is close to 100%. 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 2,174 real cases since 1980, evidence suggests that qualified field polygraph examiners are 98% accurate in their overall decisions (Ansley, N. 1990 The validity and reliability of polygraph decisions in real cases).
While the polygraph technique is highly accurate, it is not infallible and errors can occur. According to the American Polygraph Association over 250 studies have been conducted on the accuracy of polygraph testing during the past 25 years. Recent research reveals that the accuracy of the new computerized polygraph stytem is close to 100%.
The polygraph is extremely accurate. Different testing formats will yield different percentage accuracy rates. The most reliable is a specific issue examination. Results from a polygraph will be Deception Indicated (DI), No Deception Indicated (NDI) or Inconclusive/no opinion (INC or NO). While most cases will be determined during the polygraph, sometimes an examination will be inconclusive. This means no opinion is rendered as to deception or truth.
