Table 5.

Functions and features that caused deteriorated usability of the Few Touch application.

Function and feature	Design concept	Reality	Affected components in usability
User interaction design enabling nutrition habit recording completed by just one press on the appropriate category.	Users would record each meal, snack and drink immediately. Users could record food or drink intake with minimum effort.	Participants made several records at a time or recorded nutrition habits at the end of the day to summarize their food intake so that they needed more operations at a time. (P01, P03, P05, P06, P08, P10 and P12, Meeting 2) It was not always possible to record right after eating or drinking, or due to constraints of time and place. (P07, Meeting 6)	Efficiency, flexibility
Categorization of nutrition habit recording	Categories would correspond to types of eating habits that should be improved in context of T2DM, so that it encourages users to have a healthier diet.	The categorization was not precise enough for their reflective thinking, or it did not match the participants’ individual preferences based on their accumulated personal experiences. (P01, P02, P08, P11 and P012, Meeting 4)	Effectiveness, flexibility
Step counter attached on belt	A physical activity sensor should be integrated with their daily tools and outfits.	One participant (P06) did not use a belt normally. P06 had used it in a bag, but it was easy for P06 to forget about using the step counter on the next day. (Meeting 6)	Satisfaction
Step counter as a physical activity sensor	Physical activity sensor system should provide easily interpretable values to motivate a user to monitor.	The fact that other types of sports (skiing) or physical activities were not measured was disappointing. (P11, Meeting 4; [41,42] P12, Meeting 6)	Effectiveness, satisfaction
User interface of tips function and its contents	Tips function would provide a user with concise information that can be shown on a screen without necessity of scrolling or more manual operation than one button press to access to a “tip of the day”.	Participants wanted better access to information that they want to read (P05, P08, and P09, Meeting 5)	Efficiency, satisfaction
		Participants wanted more and richer information (P01, P03, P09, and P12, Meeting 4), preferably delivered by SMS with tailored contents based on user’s profile (P12 [42])	Satisfaction
Diabetes Diary as a software on a smartphone	Users would easily access to their records and information relevant to self-management of diabetes by integrating necessary functionalities into a software application running on their personal mobile phone.	A participant (P04) stopped using the smartphone as his/her personal mobile phone, because it had problems as a mobile phone (Meeting 6)	Effectiveness, efficiency, satisfaction