“…Research fields include the USA, European countries, Latin America and other regions. Research has previously considered a six-month time period from several cities in the USA (Li et al , 2020; Luo and Xu, 2021; Tian et al , 2021; Xu, 2021) and the UK (Mathayomchan and Taecharungroj, 2020; Rahimi et al , 2022). Some studies narrow their research down to only fine-dining restaurants (Cassar et al , 2020; Harba et al , 2021; Saydam et al , 2022; Tao and Kim, 2022), green restaurants (Park et al , 2021) or single chain restaurants (DiPietro and Levitt, 2019); a sample may be formed randomly from collected reviews (Oh and Kim, 2021) or filtering and only studying positive ones in depth (Ahmad and Guzmán, 2021).…”