## 4 Results
### Results of IPA  
The results for importance and satisfaction could be used to plot the IPA matrix as shown in Table 5 and Figure 1. According to the results of the IPA, safety in boarding and disembarking from the bus (1), cleanliness of vehicles (5), and punctuality of buses according to the schedule (11) were the top three attributes that had a large gap between importance and satisfaction. This can imply that these attributes had a high importance for commuters, but the provider could not provide the service adequately. which made the commuters dissatisfied. Passengers may feel unsafe if the driver is driving recklessly, stopping suddenly or accelerating too quickly, or not paying attention to passengers boarding or exiting the bus. Meanwhile, punctuality is a basic requirement for passengers to accept bus services, but the traffic congestion in Bangkok makes the punctuality of buses very poor. Moreover, there could be two possible reasons for unclean vehicles: the company's neglect in vehicle maintenance or human-caused pollution due to overcrowding by too many passengers. On the contrary, availability of online bus schedules on the internet or a mobile application (9) was the attribute that could satisfy the commuter the most because it has the smallest gap between importance and satisfaction. In Figure 1, the upper left quadrant is labeled \"Concentrated\" and contains attributes that were deemed essential by customers. Therefore, attributes falling within this quadrant should be prioritized for improvement. The results showed that there were attributes plotted in this quadrant--safety in boarding and disembarking from the bus (1), bus attendants' attitudes and helpfulness (4), cleanliness of vehicles (5), convenience of a fare payment system (10), and punctuality of buses according to the schedule (11). These attributes originated from the interaction with passengers, tangible service equipment, convenience of service, and operating management support dimensions. The second quadrant on the upper right Is called \"Keep up the good work\". Attributes plotted in this quadrant were considered necessary by customers and met their expectations, resulting in a relatively high level of satisfaction. The results showed that there were four attributes plotted in this quadrant--drivers' attitude and helpfulness (2), the skill/ability of the driver in operating the bus (3), security against crimes on buses and at stops (7), and availability of the bus schedule and route information (8). These attributes originated from the interaction with passengers, tangible service equipment, and convenience of service dimensions. The attributes included in this quadrant are crucial to maintain as they contributed significantly to the products/services' superior perception by the users. The third quadrant on the lower left is called \"Low priority\". It contains the attributes of service quality that were considered less important by customers. There were two attributes plotted in this quadrant--bus condition (6) and availability of online bus schedules  
Figure 1: IPA matrix for Bangkok bus service. Note: The numbers in the figure represent the identification numbers of the attributes.