Notify Assist: Balancing Privacy and Convenience in Delivery of Notifications on Android Smartphones

Today, notifications have become a popular medium for mobile applications to inform users about a variety of events. Android supports lock screen notifications to aid the convenience of users in viewing notification content. To address privacy concerns, Android provides platform support to applications so that they can mark sensitive notifications as private. For users, Android provides settings so that users can choose whether content of sensitive notifications should be visible on lock screen or kept hidden. However, we found that majority of the applications mark most of their notifications as private. Consequently, in choosing a particular notification setting, users face a major trade-off between privacy and convenience. In this paper, we present a system called Notify Assist, that helps users balance privacy and convenience in consuming notifications. We discuss results obtained from one year of field study, during which Notify Assist was available in Google Play Store, and a one month lab study with 60 Android users where we obtained more detailed data to supplement the field study.