Table 1.

Differences between the UIs.

Design feature	Optimized UI	Basic UI
Type of responsive design	Mobile-first	Desktop-first
Navigation menu	Three main sections presented with headlines and pictograms	One main section presented with headline only
Division of content	Subsections, pages and expandable learn-more options	Subsections
Presentation of content	Presented in small chunks	All content in one scrollable page
Exercises	Stepwise fashion	Full intervention presented on one page
Instructions	Separate instructions at each step	All instructions provided on one page
Examples and suggestions	Presented within expandable containers	Presented directly as part of the rest of the content
Automated features	Text entered in previous steps in exercises automatically synched to upcoming steps when relevant; Automatic pop-ups within exercises containing control questions and encouraging words; New subsections based on initiated problem-solving attempts	None

UI, user interface.