Factors affecting the speed of acquisition of tabulated information from visual displays

Abstract

The task studied was that of reading tabulated information following a change in the locus of fixation. Tasks of this type are involved in using telephone directories, in looking from documents to screen in conversational use of VDUs, and in reading entries in tables presented on a display. Subjects fixated a marked point on a VDU, and then looked across to an entry in a table of three-digit numbers. This was read out, and the overall reaction time recorded. This was found not to vary with the vertical position of the entry in the table, for viewing distances of 570, 885 and 1140 mm. The horizontal angular separation was varied both within the display and by means of viewing distance. Reaction times increased with separation of the initial fixation point and the target for a fixed viewing distance. Changes in angular separation due to viewing distance had little effect. Eye movement recordings showed that the latency of eye movements was constant, but that the latency of response following a displacement of fixation varied in the same way as the overall reaction time.

Keywords:

• Eye movements
• Reaction times
• Visual displays