Using data matching to compare subjective assessments of daylighting environments between Singapore and Nanjing

This study compares subjective evaluations of daylighting environments from two universities: the Singapore University of Technology and Design (SUTD) in Singapore and Southeast University (SEU) in Nanjing, China. Two hundred and twenty-nine students evaluated their instantaneous daylighting environments. Four representative daylighting predictors, horizontal illuminance, vertical illuminance, mean luminance of an entire scene and CIE Glare Index (CGI), were matched between two universities using a propensity score matching method. Eighty-eight participants, 44 from each university, were matched in terms of these four daylighting predictors. The results demonstrate that there are statistically significant differences in subjective assessments between these two locations. Under quantitatively similar daylighting environments, more participants at STUD reported adequate daylighting levels with a noticeable degree of daylight glare, as well as desires to decrease current daylighting levels. On the other hand, more participants at SEU reported inadequate daylighting levels with an imperceptible degree of daylight glare, as well as desires to increase current daylighting levels. One reason for subjective assessment differences might be dissimilar socio-environmental contexts, where the participants are acclimatized to different daylighting environments between Singapore and Nanjing.