considerable interest, including whether the polygraph leads are connected to a polygraph or a bogus source of chart output, how the physiological responses are translated into chart output (e.g., electrodermal response measured as resistance or conductance), how the questions are asked, and how often screening is done. We found no such field experiments in the entire literature on polygraph validity.

Significant obstacles to high-quality polygraph field research are readily apparent. Good field research may require substantial funding, interagency cooperation, and enough time to resolve major logistical, ethical, interprofessional, and political problems, especially when experimental manipulation is intended. Nevertheless, so long as these obstacles are allowed to impede research, the scarcity of good field studies will remain a substantial impediment to appraising the scientific validity of the polygraph.

Some of these obstacles could be overcome. For the sake of discussion, we suggest what field studies of polygraphy would be like if they adhered to the highest standards of scientific rigor. Experimental studies would randomly assign subjects to one of two or more methods for detection of deception. These might be selected using the subtraction principle: e.g., one method might be the Test of Espionage and Sabotage (TES), conducted according to current U.S. Department of Energy practice, while the other might be the same test using polygraph tracings fed into the instrument from another subject, perhaps in an adjacent room, a bogus pipeline. Or one method might be a specific-incident control question polygraph test that represented electrodermal response as either skin conductance or skin resistance, with all other factors totally comparable. In either case, research subjects and, to the extent feasible, polygraph examiners and quality control chart scorers would be blinded to which form of testing was used. Subsequently, information would be obtained about test accuracy for each individual by some method that assesses truth independently of the polygraph test result. (Perhaps the test results would be filed away and not acted on.) The data to support the truth categorization would be collected uniformly and in a standard fashion over time, without regard to which form of polygraph test the subject had taken or the test results. After testing a large number of examinees and observation over a sufficient period to determine truth, the best procedure would be determined according to some predetermined criterion, such as the method that identifies the most spies for each false positive result. If randomized experimentation could not be done, data would be collected in a uniform fashion on whatever testing was performed and compared against truth, determined in a uniform fashion independent of test results.

It is easy to see from an organizational point of view why such re-



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