Visual performance on CRT screens and hard-copy displays

Three experiments examined the effect of hard-copy print and CRT screens of different resolution/addressability ratios (RAR) on accommodation and visual search performance. Three different display modes were generated with an IBM personal computer and a Princeton Graphics Terminal: capital letters in high-RAR mode, capital letters in low-RAR mode, and capital letters in high-RAR mode programmed to simulate the low-RAR mode. Same-sized letters were also presented on hard-copy print. Experiment 1 demonstrated that accommodation to hard-copy print and high-RAR screens was more accurate than to low-RAR screens. In Experiment 2 the spatial frequency channels activated by each display were evaluated by measuring the effect of display adaptation on the contrast-sensitivity function. The results suggested that high-RAR screens and hard-copy print activated higher-frequency channels than did low-RAR screens. In Experiment 3 significantly better visual search performance was obtained for high-RAR screens and for hard-copy print than for low-RAR screens. It was concluded that screen RAR is an important variable to consider in the design of CRTs.