Angle of Hard Copy and Text-Editing Performance

Abstract

Three experiments evaluated the effect of angle of hard copy on text-editing performance. In the first, as the angular discrepancy between the hard copy and VDT screen increased, so did editing times and errors; experienced computer users generally outperformed naive users. The second experiment replicated the first but added text highlighting and a secondary task involving cancellation of a text/background screen reversal as factors. This study confirmed many of the results of the first. The secondary task response times showed consistent but nonsignificant effects of angle. Whether or not the line currently being edited was highlighted did not affect performance. The results of the third experiment suggested that having the hard copy orthogonal to the line of sight is important; in addition, it should also be adjacent to the VDT screen. These data argue for adjacent configurations that are normal to the line of sight. Subjective preferences generally supported this contention.