The year 1950 marked the halfway point for the development of polygraph testing, as we know it in 1999. Most of the instruments were two-channel mechanical units (cardiograph and pneumograph). The most widely used technique was relevant-irrelevant (RI). Among the many shortcomings in 1950 was a lack of agreement on what constituted deception criteria. Add inadequate chart markings, and that independent analysis of someone else’s charts was difficult, and the results were problematic. In this paper, 16 studies or reports which included something on deception criteria are listed. The 16 studies or texts did not discuss rank order scoring; only 2 had a form of numerical analysis, and computers were not yet useful machines. References and attachment