## 2 Literature Review
### The Kano Model  
Traditionally, customer satisfaction has been regarded as one-dimensional or symmetric: the higher the perceived product/service quality is, the higher the customer's satisfaction is and vice versa [23]. However, continuous improvements in product/service attributes without considering what customers actually want may not engender a higher level of customer satisfaction. Some researchers argued that the relationship between attribute performance and customer satisfaction is nonlinear or asymmetric [23; 24; 71]. Consequently, [PERSON] et al. (1984) introduced a two-dimensional model, called the Kano model, that clarifies the asymmetric and nonlinear relationship between product/service attribute performance and customer satisfaction, and classifies the attributes into five categories, namely, must-be factors, one-dimensional factors, attractive factors, indifferent factors and reverse factors [72]. Later, the simplified [PERSON] model classifies attributes into the following three factors, basic, performance and excitement factors corresponding to must-be, one-dimensional, attractive factors [73], which has been widely used in different research domains, as shown in Figure 1.  
1. Basic: These attributes are the basic requirements of product/service. Customers are extremely dissatisfied when these attributes don't meet their expectations. However, when customer expectations are exceeded, customers are just neutral since they take it for granted. 2. Performance: The performance of these attributes is positively and linearly related to customer satisfaction. In other words, the customer satisfaction increases with the increase in attribute performance, and vice versa. 3. Excitement: When the performance of these attributes exceeds customer expectations, customers are satisfied, but they are not dissatisfied when these attributes are absent. Therefore, good performance of this category has a stronger impact on customer satisfaction than its poor performance. Identifying different categories of attributes is beneficial for hotels to understand the determinants of customer satisfaction and dissatisfaction, and hence improving service attributes effectively [29; 74]. Many scholars have applied the Kano model to understand customer expectations and perceptions toward different service attributes in hospitality research, as shown in Table 1. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Literature** & **Objective** & **Classifying Method** & **Sample Source** \\ \hline [PERSON] et al., (2009) [75] & \begin{tabular}{c} Offer enhanced value to the hotel customer through low \\ prices while meeting appropriate features using refined \\ Kano model and a strategic price model. \\ \end{tabular} & [PERSON]’s method & Questionnaire \\ \hline [PERSON] and [PERSON] (2011) [27] & \begin{tabular}{c} Use the Kano model and quality function deployment \\ (QFD) to explore hotel brand contact elements perceived \\ by customers. \\ \end{tabular} & [PERSON]’s method & Questionnaire \\ \hline [PERSON] et al., (2017) [76] & \begin{tabular}{c} Explore nonlinear effects of service quality on customers’ \\ evaluation of three-star hotels in Rio de Janeiro, Brazil. \\ \end{tabular} & CIT and PRCA & TripAdvisor.com \\ \hline [PERSON] and [PERSON] (2016) [30] & \
\begin{tabular}{c} Integrate IPA with the Kano three-factor theory to examine \\ the difference of service attribute importance in different \\ market segments using the case of luxury hotels in Macau. \\ \end{tabular} & Importance grid & Questionnaire \\ \hline [PERSON] and & Identify customer needs for the hotels and prioritize them \\ [PERSON] (2017) [12] &
\begin{tabular}{c} Identify customer needs for the hotels and prioritize them \\ using a combination of the SERVQUAL and \\ Kano approaches. \\ \end{tabular} & [PERSON]’s method & Questionnaire \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Related studies of Kano model in hospitality research. Figure 1: The Kano model.