# Measurement of Circadian Effectiveness in Lighting for Office Applications
## 4 Discussion
Thus, a systematic and accurate characterization of these errors to delineate the worst-case scenario seems to be indicated and should be performed as part of future research. In addition, working towards an improvement of [PERSON] et al. 's approximation method of Equation (5) to achieve an adequate modeling of not only white light sources but also monochromatic or colored emitters may in general lead to a better overall model performance. Finally, it should be noted that, for an accurate prediction of non-visual effects on human outcome measures from in-field light measurements, the timing and duration of light exposure also need to be considered. As it was confirmed empirically in the past [44; 65], circadian effectiveness is not only a matter of spatial light distribution, spectral composition, and intensity but also determined by the time people are exposed to a certain illumination or light condition. For that reason, future developments for an improved validity and interpretability of light measurements in the non-visual domain must account for the possibility of including temporal light exposure profiles that predict the timing and duration an individual is expected to be exposed to a certain lighting condition. Wearable, sensor-based light tracking over longer duration periods that allows for a time-resolved collection of light information can thus be a valuable tool for the derivation of such characteristic, context-dependent temporal light exposure patterns. By complementing the concepts of a directional and gaze-dependent weighting of lighting contributions, the explicit inclusion of temporal information may allow for a better and more comprehensive prediction of the non-visual effects that can be expected from in-field light measurements using the spatially resolved measurement framework proposed in this work. **Author Contributions:** Conceptualization, S.B. ([PERSON]), S.B. ([PERSON]), J.K. ([PERSON]), and P.M.; Data curation, S.B. ([PERSON]), J.K. ([PERSON]) and S.B. ([PERSON]); Formal analysis, J.K. ([PERSON]), S.B. ([PERSON]), [PERSON] ([PERSON]), [PERSON] ([PERSON]), and [PERSON]; Methodology, [PERSON] ([PERSON]), [PERSON] ([PERSON]), and T.Q.K. ; Software, [PERSON] ([PERSON]), [PERSON] ([PERSON]), and [PERSON] ([PERSON]); Supervision, T.Q.K. ; Validation, [PERSON] ([PERSON]), [PERSON] ([PERSON]), P.M., and [PERSON] ([PERSON]); Visualization, [PERSON] ([PERSON]), [PERSON] ([PERSON]), and [PERSON] ([PERSON]); Writing--original draft, [PERSON] ([PERSON]), [PERSON] ([PERSON]), and [PERSON] ([PERSON]); Writing--review and editing, [PERSON] ([PERSON]), [PERSON] ([PERSON]), [PERSON] ([PERSON]), [PERSON] ([PERSON]), [PERSON], [PERSON] ([PERSON]), and [PERSON]; Project administration, [PERSON] ([PERSON]), [PERSON] ([PERSON]); Funding acquisition, [PERSON] ([PERSON]), and [PERSON]. All authors have read and agreed to the published version of the manuscript. **Funding:** This work was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Grant No. 445336968 and by the Open Access Publishing Fund of Technical University of Darmstadt. [PERSON]. ([PERSON]) received personal funding by the Ernst Ludwig Mobility Grant of the Technical University of Darmstadt. **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable. **Data Availability Statement:** All data generated or analyzed to support the findings of the present study are included this article. The raw data can be obtained from the authors, upon reasonable request. **Conflicts of Interest:** The authors declare no conflict of interest.