Exploring Expandable-Grid Designs to Make iOS App Privacy Labels More Usable

People value their privacy but often lack the time to read privacy policies. This issue is exacerbated in the context of mobile apps, given the variety of data they collect and limited screen space for disclosures. Privacy nutrition labels have been proposed to convey data practices to users succinctly, obviating the need for them to read a full privacy policy. In fall 2020, Apple introduced privacy labels for mobile apps, but research has shown that these labels are ineffective, partly due to their complexity, confusing terminology, and suboptimal information structure. We propose a new design for mobile app privacy labels that addresses information layout challenges by representing data collection and use in a color-coded, expandable grid format. We conducted a between-subjects user study with 200 Prolific participants to compare user performance when viewing our new label against the current iOS label. Our findings suggest that our design significantly improves users' ability to answer key privacy questions and reduces the time required for them to do so.