A Multi-Group Usability Evaluation of a Human-Centred Privacy and Permission Management Framework (MIDA)

Users encounter privacy and permission settings across digital platforms, yet often struggle to understand, locate, and manage them effectively. Despite regulatory efforts such as the General Data Protection Regulation (GDPR) and platform mechanisms like App Tracking Transparency, these challenges persist due to interface design limitations rather than solely user capability. This study evaluates the My Information and Data Access (MIDA) framework, a user-centred privacy interface designed to support users with different levels of expertise. A between-subjects usability study was conducted with 44 participants (novice n = 15, intermediate n = 14, advanced n = 15), combining System Usability Scale (SUS) scores, task completion rates, error rates, and think-aloud protocols. The results show high usability across all groups, with SUS scores of 80 (novice), 84 (intermediate), and 92 (advanced), all exceeding the acceptability threshold of 68. Task completion rates exceeded 80%, whilst error rates remained below 25% across most tasks. These findings indicate that MIDA can support users in understanding, configuring, and managing privacy settings across different levels of expertise. This study builds on prior HCI research linking privacy management challenges to interface design limitations and provides empirical evidence that an expertise-adaptive interface can improve users’ ability to understand and manage privacy settings.