Effect of Glare on Performance of a VDT Reading-Comprehension Task

Abstract

This study was undertaken to determine whether objective measures of reading performance are affected by short exposure to text on a display when glare is present. Reading performance was assessed using reading time and correctness of answers as measures. In a preliminary experiment 20 reading passages were ranked according to subjective reading difficulty and also according to an objective measure. Subsequently, in the main experiment subjects read the 20 passages presented on a VDT under both no-glare and glare conditions. When task difficulty was measured by subjective ranking, glare was found to increase the amount of time required to read relatively easy passages and to decrease the amount of time required to read relatively difficult passages. Other findings included a general increase in reading time and a decrease in the proportion of correct answers with increases in task difficulty for both subjective and objective ranking of difficulty.

Get full access to this article

View all access options for this article.

References

Bartolucci, A. A. , and Fraser, M. D. (1977). Comparative step-up and composite tests for selecting prognostic indicators associated with survival. Biometrika Journal, 19, 437–448.

Bodmann, H. W. , and Sollner, G. (1965. June). Glare evaluation by luminance control. Light and Lighting, 58, 195–199.

Boyce, P. R. (1973). Current knowledge of visual performance. Lighting Research and Technology, 5(4), 204–212.

Hollander, M. , and Wolfe, D. A. (1973). Nonparametric statistical methods (pp. 201–206). New York: Wiley.

Holladay, L. L. (1926). The fundamentals of glare and visibility. Journal of the Optical Society of America, 12, 271–319.

Hopkinson, R. G. (1972). Glare from daylighting in buildings. Applied Ergonomics, 3(4), 206–215.

Hultgren, G. V. , and Knave, B. (1974). Discomfort glare and disturbances from light reflections in an office landscape with CRT display terminals. Applied Ergonomics, 5(1),2–8.

Lulla, A. B. , and Bennett, C. A. (1981). Discomfort glare: Range effects. Journal of the Illuminating Engineering Society, 10(2), 74–80.

Shapiro, S. S. , and Wilk, M. B. (1965). An analysis of variance for normality (complete samples). Biometrika, 52, 591–611.

10.

Smith, E. A. , and Senter, R. J. (1967, November). Automated Readability Index (Tech. Report AMRL-TR-66–220). Wright-Patterson Air Force Base, OH: Aerospace Medical Research Laboratories.

11.

Stone, P. T. , and Groves, S. D. P. (1968). Discomfort glare and visual performance. Illuminating Engineering Society-Transactions (London), 33(1), 9–15.