The Effects of Divided Attention on Visual Monitoring of Multi-Channel Displays

This study Investigated the effects of divided attention on monitoring multi-channel alpltamerlc displays for signals defined on the basis of the simltuaneous Values of all channels, i.e., multi-channel signals as opposed to single-channel signals. Variables Investigated Included (a) three methods of dividing attention (a short writing task, a long writting task, and blanking out the display), (b) number of channels monitored (4, 8, 12, and 16), (c) rate of display change (6 or 12 times per minute), (d) number of different signals simultaneously watched for (8 or 24), and (e) number of levels within channels (2 or 8). The main results were: (a) divided attention did not lead to a decrease in monitoring, compared to a control study without divided attention; (b) the rate of display change had the greatest effect upon performance, followed by the number of channels monitored; (c) even at the faster rate of display change, untrained subjects detected 80% or more of the signals when they monitored up to 12 channels: and (e) different methods used to divide attention affect performance differentially. © 1967, Human Factors and Ergonomics Society. All rights reserved.