In broad daylight: An investigation of the multiple environmental factors influencing mood, preference, and performance in a sunlit workplace

This research investigated joint influences of several environmental factors, which include outdoor view, sunlight, privacy, and control, on subjects' mood, perception, cognitive performance and preference in a daylit work environment. An experiment with one hundred subjects showed that subjects' sitting positions significantly affected their mood and cognitive performance. The amount of daylight and sunlight penetration alone, however, was not evident for performance; instead, the combined effect of sunlight, outdoor view, privacy, and control was correlated to subjects' cognitive performance. This combined effect at a level of sixty percent was optimal for cognitive activities. The study result also suggested that room occupants' cognition was mediated by their mood and perception. In other words, various compositions of environmental conditions were affective sources that conveyed emotional meanings to room occupants and thus influenced their behavior. Furthermore, Investigations of the declared preference of sitting area and subjects' cognitive performance indicated that people are not always aware of the environmental factors that influence their behavior. Subjects were generally attracted to sunlight and outdoor views, but they did not necessarily perform best in these preferred areas. Privacy and a sense of control were two hidden factors that greatly affected subjects' decision and performance. This research, for the first time, made a comprehensive evaluation of a sunlit environment from an architectural point of view, which is focused on the space where daylight is defined. It revealed that the commonly believed benefits of daylighting on improving performance take effect on condition that the other factors are in an optimal range. This knowledge would help architects better understand the relationship between daylighting and human behavior and thus design better daylit environment, where room occupants are happier and more productive.