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Four major display variables, luminance adaptation level, symbol contrast ratio, symbol visual size and off-axis viewing angle, were related, in a rotatable central composite design, to an observer's ability to identify symbols shown on a large screen display (LSD). The results show the nature and significance of all main effects as well as delineate the important interactions among these variables. The results can be used as an LSD design and evaluation tool permitting tradeoffs to be made among the important features of display equipment, projection screens and viewing facilities.

Perceptual enhancement for image motion in the visual periphery was evaluated by threshold measurements with a moving-bar stimulus. Lowered peripheral thresholds were found for both forward and backward image movement with no significant elevation of the contrast threshold for an image in motion out to 55° eccentricity from the fovea. Either real or phi-phenomenon movement is recommended for the display of emergency or mission-critical signals.

Advances in the design of radar data processing and display systems have resulted in certain nonlinearities in the response of the displayed cursor to a manual input. This paper examines the effects upon target acquisition time, in a simulated air defense environment, of (1) a low-velocity “dead zone” for which no cursor movement occurs, and (2) quantization of control velocity into a small number of discrete cursor velocities. Resulting decrements in acquisition latencies are given as functions of tracking distance and direction. A rolling ball control is used.

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