“…However, the model is linear in nature and cannot handle the non‐linearity issue. Therefore, multiple machine learning techniques (e.g., machine learning, random forest, AdaBoost decision tree, and extreme gradient boosting) are recommended (Xiao, Lo, Liu, Zhou, & Li, 2021; Lu et al, 2021, 2022; Lu and Chen, 2022) to unravel the complicated relationship between the built environment and the walking behavior of older people to draw more accurate and persuasive conclusions. Moreover, incorporating simultaneous estimation thinking into machine learning techniques (for two or more predicted variables) is to be applauded.…”