A method for evaluating the use of the polygraph in a real-life situation.

Previous attempts to evaluate the polygraph in a real-life·situation suffered from several defects, The present study attempts to eliminate these defects by meeting six necessary conditions for an acceptable real-life validation of the polygraph. The procedure devised guarantees the objective identification oL"liars," without jeopardizing the real-life appearance of the experimental situation. Fifteen sub­ jects participated in the experiment; two ofthem actually cheated on a test. All subjects went through .a standard polygraph test using the control questions method. Each subject was evaluated by three polygraphers. One had access to the polygraph charts only, one observed the subject's behavior but not his charts, and a third, who conducted the interrogation, had both kinds of information. The evaluations of all three were. compared with the criterion. The evaluations that were based both on behavior observation and on the physiological charts were superior to those based on either type of information alone. However, the evaluations based on the physiological information alone were not superior to those based on the behavioral information alone, Polygraphic interrogation is a very im­ portant area of applied psychology, both in terms of the extent of its use and in terms of its social ramifications (Lykken, 1974), However, very few validity studies concern­ ing the use of the polygraph in real-life sit­ uations have been done, and the interpre­ tation of these few studies is highly controversial (Lykken, 1979; Raskin & Pod­ lesny, 1979). The interrogation method most frequently