From introduction: "Developed and perfected for years, polygraph examination techniques have probably reached the limits of their capabilities. Their diagnostic value is comparable to that of other techniques routinely used in investigations (Widacki 1977, Widacki & Horvath 1978). Neither new examination techniques nor new kinds of tests are likely substantially to affect this conclusion. Granted, whereas whether it is possible to improve the diagnostic value by another 1 % and increase the number of conclusive results may be of significance for practice, this remains more an issue of perfecting practice rather than a scientific problem."(...)