Supporting People with Acquired Brain Injury to Use a Reminding App; Narrow-deep vs. Broad-shallow User Interfaces

AbstractPeople with memory impairments following an acquired brain injury stand to benefit from smartphone apps as memory aids. Due, in part, to usability issues they use smartphone-based reminding less than the general population. Evidence suggests this group may benefit from user interface (UI) designs with more screens with less information per screen (narrow-deep UI) rather than fewer screens with more information per screen (broad-shallow UI). This study compared the difference in speed, accuracy, guidance needed, and task load for 32 people with acquired brain injury when setting reminders using narrow-deep and broad-shallow UI. They were also given cognitive assessments (measuring selective attention, executive functioning, and overall executive and memory ability) and interviewed about their UI preference. There was a significant difference in accuracy; participants were less accurate (they made two more errors on average for every three reminders set) using a broad-shallow compared to narrow-deep UI. The reason for this difference was that participants omitted more information when using broad-shallow UI. There were no differences in speed, guidance required, and overall task-load. Participants with better selective attention and more experience with smartphones benefited the most from narrow-deep UI compared to broad-shallow UI. Most participants preferred one UI over the other. Those who preferred narrow-deep found it easier to use, that they missed less information and liked having one piece of information at a time. Those who preferred broad-shallow found it easier to review the information and felt less likely to lose track. The findings can inform that implementation of UI choices to make apps more accessible for those with cognitive impairments.