Determinants of lighting quality I: State of the science

Members of the lighting community have long speculated about the effects of lighting quality on human performance, comfort, and well being. This debate has become particularly heated as energy conservation has increased in importance, and building energy codes have reduced the power available for lighting. Past attempts to develop a metric for lighting quality, even in the limited case of office lighting, have largely failed. One important reason for this failure is had science: bad research, design, statistical analysis, and reporting. The limitations include the use of abstract tasks for visibility measurements, a narrow range of behavioral outcomes, and inadequate specification of the population to which the data apply. This paper proposes that lighting quality research be recognized as a subset of environment-behavior research and presents a behaviorally based definition of lighting quality. Selected examples from the lighting literature that fall within this definition are reviewed. Adherence to the common practices of the behavioral sciences promises improved knowledge of lighting effects on behavior that researchers can bring to interdisciplinary discussions for consensus-based lighting design recommendations.