Reliability
Reliability analysis was performed on the basis of both internal consistency and interrater agreement methods. First, Cronbach's alpha was found to be 0.89 for expectation-related items and 0.93 for perception-related items. As a second analysis, the within-group agreement index rwg(j) was used to evaluate interrater agreement. The rwg(35) was 0.97 for expectation-related items and 0.96 for perception-related items; scores supporting reliability.
4.2. Validity
The questionnaire was constructed with an acceptance of the general validity of the SERVQUAL (Zeithaml et al., 1990). A pilot test was conducted and company executives’ opinions about the questionnaire confirmed content validity. Exploratory factor analysis was performed with varimax rotation and 8 factors were extracted from the expectation data set via principal components analysis (PCA). These factors are labeled as (1) employees, (2) tangibles, (3) responsiveness, (4) reliability and assurance, (5) flight patterns, (6) availability, (7) image, and (8) empathy. Factor loadings are given in Table 2. They were perceived as service quality dimensions for the purposes of our study and are compatible with previous research, indicative of the validity of the study. The cross-match of dimensions is given in Table 3. As we see, “reliability” is renamed as “reliability and assurance”. In addition to existing factors, “availability” and “image” were newly produced as results of PCA.