Personal control over workplace lighting: performance and mood effects
Date
2018-07-03
Authors
Veitch, Jennifer Ann
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Abstract
Lighting research has produced a wealth of knowledge concerning the visual effects of workplace lighting, but little understanding of other behavioural consequences. One trend in current lighting practice is toward providing users with the opportunity to control their own workstation lighting, often through the use of supplementary task lighting. The general assumption is that personal control over lighting will lead to better performance and improved mood. The personal control literature in psychology is abundant and tends to support this belief. Environmental psychologists in particular have embraced the idea that the provision of choices in the physical environment will lead to desirable outcomes, such as feelings of self-efficacy or competence.
The present study tested the notion that personal control over lighting has beneficial effects, using a modified 2 x 2 Control x Preference factorial design with an additional control group to test for the possibility of subject reactivity biases. The Preference variable was included to test the hypothesis that working under favoured conditions, regardless of one's ability to control them, beneficially affects performance and mood. The design incorporated measures of motivation and attention to attempt to distinguish between two competing mechanisms that might underlie the effects. Male and female undergraduate students were randomly assigned to one of the five conditions in this laboratory experiment for a 2-hr session during which they completed a mood questionnaire and intellectual tasks including brain-teaser puzzles, a creativity task, an arithmetic task, and a grammar worksheet.
The manipulation of Control as well as the manipulation of Preference (for the lighting at which one worked) affected ratings or perceived control. Subjects in the Control condition reported higher feelings of control than those in the No Control Condition; similarly, Preference Given subjects rated their perceptions of control more highly than Preference Denied subjects.
Contrary to the conventional wisdom among environmental psychologists and designers, the results showed that choices in the physical environment are not always beneficial, at least where lighting is concerned. Control subjects performed more poorly on the intellectual tasks and more slowly on the creativity task than No Control subjects. The outcomes are discussed as differential effects of decisional versus cognitive control. Design applications of the personal control construct await further research.
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Keywords
Work environment, Lighting, Psychological aspects, Office buildings, Work