Table 5.

Summary of design guidelines for interface elements.

Interface element (theme)	Example of interface element (subtheme)	Summary of design guidelines
Education	Introduction page	System designers should consider how fast users adapt to the system and, at the same time, how easy or hard the system was designed since these factors influence the user’s need for an instruction page.
Goal setting	Default setting, adjusted setting (customizable)	System designers should consider the user’s willingness to manage the eye condition since it decides a need for customization of goal settings. Default setting is the predefined setting regardless of the user’s autonomy.
Monitoring	Participation report	This element can be a double-edged sword for the motivation of the user. It can increase or decrease the self-efficacy of the user depending on the level of participation.
Feedback	Default message, compliment after eye resting	Depending on the context of the user, it can be either effective or ineffective. However, the preference for this element was high among users.
Information delivery	Health information	System designers should consider the user’s intention to manage the symptoms. If the user intention is high, the need for health information is also high at most times. However, low user intention can make users feel that this element is a burden.
Notification	Size of the window	The size of the popup influenced the forcefulness of the computer-based intervention. The full-screen notification with the high forcefulness was evaluated as most effective, but, at the same time, a high burden. Mid-size notifications positively affected user participation among other options.
Medium	Sound	The social context largely affected the user experience. Most of the participants insisted that it does not need to be in the system.
Aesthetic	Presence of characters (expert agent or robot agent) or visual effects (symptom-like effects)	Most of the time aesthetic elements rarely affect user participation, except when they strengthen the intervention effects by accompanying other intervention elements, such as the notification window in our case.