Time in human-computer interaction: performance as a function of delay type, delay duration, and task difficulty

Abstract

Human-computer interaction comprises two time phases, System Response Time (SRT), the interval of time between user input and computer response, and User Response Time (URT), the time that elapses between computer response and user input. Delays within each of these time intervals have been shown to significantly impact performance of computer-mediated tasks.

The results of studies assessing this problem suggest that delay effects depend on the difficulty level or information processing requirements imposed by the task being performed. Time delays must be commensurate with the amount of time required to process the information associated with task decisions. As task difficulty increases, computer-imposed delays should facilitate performance by releasing the user from the time constraints associated within quick computer response rates. The effect of such delays should be to induce the user to take more time to think about the task.

The current study assessed the relationship of delays (0, 1, 2, 4, 8 seconds) within the SRT and URT time phases, and task difficulty level (Low, Medium, or High) as they relate to users' performance of a problem-solving task. Results suggest that moderate delays facilitate performance on tasks of greater difficulty, but serve no beneficial purpose for tasks that do not impose significant information processing loads.