Resumen
The existing usability models have been used primarily for evaluation, not for usability engineering. The models were found to be general for specific mobile applications. They also lack appropriate guidelines to apply the usability models to m-government applications. Earthquake information is an example of critical information delivered to citizens via m-government applications. Usability design is considered a very important key factor to the success of such applications. This research addresses the challenges in finding the usability factors important to m-government applications and choosing appropriate factors for specific m-government applications. A questionnaire was administered to 49 citizens. The results include six usability factors which are learnability, simplicity, satisfaction, security, privacy, and memorability. Descriptions of the usability factors were later added to provide a clearer definition for each factor. This paper proposes the usability design framework for m-government applications. The use of the framework was illustrated based on the user interface redesign of the EarthquakeTMD application. The main aim was to demonstrate the applicability of the framework. The quality of the original UI design of the application in the case study was assessed with a questionnaire which was administered to 57 Thai citizens who lived in the areas affected by the disasters. Four designers participated in UI redesigning and produced four different UI designs. The new UI designs were evaluated via two usability tests on two sample groups of representative users. The first usability test was conducted with 24 participants. Twenty-four test cases were used. The second usability test was conducted with 351 representative users. After the tests, both sample groups were given a questionnaire based on the SUS (System Usability Scale). The same two UI designs by experienced and inexperienced designers who used the framework received the highest scores: 89.58 and 87.60 on the first usability test. They also received the highest score on the second usability test: 89.10 and 90.88. The results reveal that the citizens preferred the new user interfaces designed using the framework. It was found that the scores of the UI designed by inexperienced designers who used the framework were as high as the scores of the UI designed by experienced designers, whereas the UI designs from the designers who did not use the framework received the lowest scores: 63.23 and 54.27 on the first usability testing and 59.34 and 46.53 on the second usability testing.