Subjective Assessments of Lighting Quality: A Measurement Review

Lighting is an important component of indoor environmental quality that can affect occupant satisfaction, well-being and productivity. Lighting quality is a broad abstract concept and this has implications for its assessment. Subjective evaluations of lighting are an important complement to objective photometric information; however, there is limited existing guidance for the selection of such measures. We review and highlight the advantages and limitations associated with measures of general lighting quality and discomfort glare. Existing measures of lighting quality have broad coverage of individual lighting features but do not always clearly form cohesive scales measuring an underlying construct. Questions used in experimental glare research focus narrowly on glare severity, with ambiguous response rating scales. There is a need for the development of reliable and valid tools to assess lighting quality and its components, with clearly defined definitions and constructs, and explicit reporting of psychometric scale properties. The development of rigorous self-report tools will improve the understanding and design of quality lighting environments.