A human factors study in which participants viewed 3-D imagery under two task conditions designed to mimic the critical information processing elements of an aircraft control application is reported. In one task, observers judged the relative distance between objects in a 3-D workspace, whereas the other task required observers to extrapolate object positions from course heading cues. Operator performance was assessed for imagery presented with or without retinal disparity cues in three display formats (i.e. , plan view, simple perspective view, and enhanced perspective view) and at three signal-to-clutter levels. The findings indicate that retinal disparity cues reduce the number and magnitude of response errors in the course prediction task, but do not affect observer's response times or ratings of response confidence. The effects of display format varied between the two tasks. In the relative distance assessment task, response times for the simple perspective format were shorter than those for the plan view or enhanced perspective formats. In the course prediction task, response times for the plan view and simple perspective formats were shorter than for the enhanced perspective format. Display format did not affect response errors, error magnitude, or ratings of response confidence.