User tracking accuracy during smooth pursuit of a target with and without a crosshair

Gaze interface is a human-computer interaction method that offers numerous benefits to users. Therefore, researchers and practitioners are investigating key design issues in gaze interfaces. In this investigation, we compared user tracking accuracy during smooth pursuit of a target with and without a crosshair. Our comparison was based on data from an experiment in which participants tracked a moving target with a crosshair that they controlled with their eyes and on data from a similar experiment in which users tracked the same target without a crosshair. Maneuvering types and velocity of the target alternated between the experimental blocks. We found that mean tracking accuracy was lower when the target was moving faster and when participants used a crosshair. Our findings suggest that the usage of pointers (e.g., crosshairs, cursors) during smooth pursuit of targets might impair tracking accuracy. These findings resonate with previous concerns about the shifting of user attention from the target to the pointer.