Understanding User Performance in Variable-Timing Moving-Target Acquisition

Moving-target acquisition (MTA) tasks require users to press a button when a moving target reaches an acquisition line. Previous studies on MTA have mainly examined cases in which the target appears repeatedly in a fixed input period, making it predictable to users when to press the button. However, this assumption does not hold in many real-world applications where temporal variability is prevalent, such as video games. Thus, this study investigates user performance in variable-timing MTA tasks where variability exists in the input period. We conducted a user study with 20 participants performing a variable-timing MTA task in which the variability of the input period followed a Gaussian distribution. We also examined how the two performance variables, mean input timing (µ) and timing precision (σ), change with task parameters such as cue-viewing time, period mean and period variability. The results showed that greater temporal variability led to later and less precise responses, with timing distributions deviating from normality due to the mixture of anticipatory and reactive strategies.