NCJ Number
35507
Date Published
1976
Length
29 pages
Annotation
THIS STUDY USED A NUMERICAL SCORING SYSTEM TO INDEPENDENTLY EVALUATE POLYGRAPH CHARTS OF SUSPECTS IN 419 CASES RANDOMLY SAMPLED FROM THE ARCHIVES OF 43 FIELD POLYGRAPH EXAMINERS.
Abstract
THE PURPOSE OF THIS STUDY WAS TO TEST THE EFFECTIVENESS OF THE VARIOUS MEASURES EMPLOYED IN POLYGRAPH EXAMINATIONS, WHETHER EXAMINERS ARE INFLUENCED BY FACTORS OTHER THAN INFORMATION PROVIDED BY THE POLYGRAPH CHARTS, AND THE EXTENT OF AGREEMENT BETWEEN INDEPENDENT EVALUATION OF POLYGRAPH EXAMINATIONS AND THE DECISIONS MADE BY LAW ENFORCEMENT AS COMPARED TO PRIVATE POLYGRAPH EXAMINERS. THE FREQUENCY AND PERCENTAGE OF CASES WHERE THE ORIGINAL EXAMINER ARRIVED AT DECISIONS OF DECEPTIVE, TRUTHFUL, AND INCONCLUSIVE WERE COMPARED TO THE RESULTS OF THE INDEPENDENT EVALUATIONS. THERE WAS 85 PERCENT AGREEMENT BETWEEN THE DECISIONS MADE BY THE ORIGINAL EXAMINER AND THOSE MADE BY THE INDEPENDENT EVALUATORS. HOWEVER, WHEN INCONCLUSIVE DETERMINATIONS WERE INCLUDED, AGREEMENT DROPPED TO ONLY 57 PERCENT. THE OVERALL RESULTS SEEMED TO INDICATE THAT MANY EXAMINERS FAILED TO USE THE INCONCLUSIVE CATEGORY WHEN IT WAS APPROPRIATE TO DO SO AND OFTEN APPEARED TO BE CONCLUDING THAT SUBJECTS WERE TRUTHFUL WHEN THE POLYGRAPH CHARTS DID NOT PROVIDE A SCIENTIFICALLY-SUPPORTABLE BASIS FOR THE DECISION. THIS WOULD TEND TO SHOW THAT EXAMINERS RENDERED DECISIONS BASED ON INFORMATION NOT CONTAINED IN THE PHYSIOLOGICAL RECORDINGS, SUCH AS BEHAVIORAL CUES, CASE INFORMATION, PREVIOUS EXPERIENCE, AND INTUITION. SIGNIFICANTLY GREATER AGREEMENT WAS FOUND BETWEEN THE INDEPENDENT EVALUATIONS AND THE ORIGINAL DECISIONS OF THE POLICE AS COMPARED TO PRIVATE EXAMINERS. RECOMMENDATIONS FOR REFORM INCLUDE REQUIRING AT LEAST THREE CHARTS FOR ALL CRIMINAL SUSPECT EXAMINATIONS WHEN CONTROL-QUESTION TESTS ARE EMPLOYED, REPLACEMENT OF RELEVANT - IRRELEVANT TESTS WITH CONTROL CONTROL-QUESTION OR GUILTY-KNOWLEDGE TESTS, AND EXAMINERS TO USE THE INCONCLUSIVE CATEGORY MORE OFTEN. REFERENCES ARE INCLUDED.