*1.8. Methodologies*

All the aforementioned empirical studies involved survey or interview responses regarding SWB and used those responses as SWB indicators. However, MacKerron and Mourato utilized an innovative method by using a smartphone application to periodically collect daily life SWB data, as well as the GIS location when respondents reported their SWB, making more frequent measurement possible [34]. As an additional exception to the physical surveys and interviews, Wei et al. used facial expressions on selfies on SNS, a possibly more objective representation of SWB, to measure the satisfaction levels of visitors to forest parks in Chinese cities [35].
