Reliability and Validity of Polygraph-Based Classification

Abstract

In the previous chapters we described various methods of psychophysiological detection and discussed their rationales. The discussion was based on logical and theoretical considerations, and it led us to conclude that only one method, the GKT, is based on a sound rationale, whereas all the other methods suffer from serious logical and theoretical flaws. The proponents of CQT polygraphy, in defending their practice, usually turn to an empirical approach, arguing that since the CQT has proved to be an efficient tool for detecting guilt or deception, the logical arguments raised against it are not relevant. In this chapter we shall closely examine the empirical approach as applied to psychophysiological detection, and in particular, we will try to clarify whether there is indeed any substantial evidence supporting the validity of the CQT.