A simple graphical technique for assessing timer accuracy of computer systems

Timing accuracy is of perennial concern to researchers conducting reaction time studies, especially for those using computers that were not designed with millisecond accuracy in mind. Inaccuracies can manifest themselves in the form of quantization of the continuous time data stream. The method proposed here is simply to inspect the graph of the order statistics because quantization is readily apparent in such graphs. The method is illustrated with timing measurements of keypresses on an IBM PC.