Computer response time and user performance.

Nearly everyone agrees that computer response time is very important to the users of interactive systems. Many papers have been written describing the bad effects of computer response times that are too long or too short, and many sets of “guidelines” for appropriate human-engineered computer response times in human-machine systems have been published, as well. Nearly all these sets of guidelines are direct descendants of the set published by Robert Miller (1968) about 15 years ago. When Miller wrote his guidelines, he was quite open in describing them as based only on his experience, and he called for experimental data that would allow for the formulation of better, empirically-based rules for setting computer response time for optimal human performance.