Preferred Lighting Levels

Typically, studies of illumination have emphasized its effects on performance of specific tasks. The present study instead examined preference for lighting levels. Among the reasons for investigating preferences is that preference measures theoretically include a variety of human reactions to lighting, including comfort, aesthetics, and performance. The purposes of Experiment 1 were to obtain preferences for lighting levels, judgments of the importance of lighting levels, and judgments about the desirability of controlling lighting level for 43 behavior settings of college students. The purposes of Experiment 2 were to replicate part of Experiment 1 and extend the research to other common behaviors occurring in the same settings studied in Experiment 1. Results indicated large differences in the variety of lighting preferred for various behaviors and settings. Judgments of importance of lighting level had a quadratic relationship to preferred illumination, that is, importance was greater for behavior settings preferred either dark or bright. Importance and control were strongly linearly related. Implications for I ES standards and future research are discussed.