“…Third, we identified domain-specific items of airline service categories from past research. A stream of studies focused on domain specific items such as involuntary denied boarding (Lindenmeier and Tscheulin, 2008;Garrow et al, 2011;David, 2013), ground service (Brochado et al, 2019;Sricharoenpramong, 2018), advertising (Tiernan et al, 2008), on-time flights, baggage reports, oversales, ticketing, refunds, fares and passenger complaints (Waguespack and Rhoades, 2014;Sithipolvanichgul et al, 2020;Baker, 2013;Atalık et al, 2019;Shen and Yahya, 2021). Lastly, we normalize these domain specific items and group them into the airline service categories: Baggage, Cleanliness, Customer service, Delays, Food and beverages, In-flight entertainment, Seating and Upgrades (See Table 6).…”