Error percentages for subjects reading a four-digit liquid crystal display were examined under various conditions by means of a response surface methodology (RSM) central-composite design. Angle of view, character subtense, level of back light, and ambient light were varied in a four-factor experiment. Multiple regression prediction equations relating these four independent variables to error-percentage rates for reading the display were calculated from a replicated, collapsed RSM design. Backlighting has an adverse effect on subjects' reading accuracy, particularly when the displays are viewed at an angle.
Get full access to this article
View all access options for this article.
References
1.
Box, G. E. P., and Wilson, K. B.On the experimental attainment of optimum conditions. Journal of Royal Statistical Society, Series B (Methodologies), 1951, 13, 1–45.
2.
Clark, C. and Williges, R. C.Central-composite response surface methodology design and analyses. Savoy, IL: University of Illinois Institute of Aviation, Aviation Research Lab, Technical Report ARL-72-10/AFOSR-72-5, June, 1972.
3.
Clark, C. and Williges, R. C.Response surface methodology central-composite design modifications for human performance research. Human Factors, 1973, 15, 295–310.
4.
Clark, C., Williges, R. C. and Carmer, S. G.General computer program for RSM analyses. Savoy, IL: University of Illinois, Institute of Aviation, Aviation Research Lab, Technical Report ARL-71-8/AFOSR-71-1, May, 1971.
5.
Duncan, J., and Konz, S.Effect of ambient illumination on legibility of displays of liquid-crystals and light-emitting diodes. In Proceedings of the Human Factors Society 18th Annual Meeting. Santa Monica, CA: Human Factors Society, 1974.
6.
Embrey, D.The reliability of the human observer as a systems component. In J. N. Clare and M. A. Sinclair (Eds.) Search and the human observer, London: Taylor and Francis, 1979.
7.
Payne, S. J., Pollard, D., and Cooper, M. B.Some ergonomic investigations of seven-segment displays. London: British Telecommunications Research Department, Report No. 891, 1981.
8.
Sinclair, M. A.A critique of the ergonomics approach to experimentation. In J. N. Clare and M. A. Sinclair (Eds.) Search and the human observer.London: Taylor and Francis, 1979.
9.
Van Nes, F. L., and Bouma, H.On the legibility of segmented numerals.. Human Factors, 1980, 22, 463–474.
10.
Williges, R. C. and Baron, M. L.Transfer assessment using a between-subjects central-composite design. Human Factors, 1973, 15, 311–319.
