- The effect of different types computer “wait” message displays on the subjective estimates of the duration of intervals in which the subject had to wait for the computer response was studied. The displays were either static (a blank screen, the phrase PLEASE WAIT, or an epigram) or dynamic (a blinking PLEASE WAIT, a round clock-like display, or an emerging string of Xs along the center of the screen). Display duration varied from 3 to 16 seconds. The dynamic displays were shown at three different rates each. Results showed differences among the displays. For dynamic displays in which a development over time can be perceived (the clock and string of Xs), there was a direct relation between the rate of change and the estimate, i.e., higher rates of change led to estimates of longer durations. The results demonstrate that some of the variables, which have been found to influence time perception in basic psychological research settings, are applicable in the user-computer setting.