Update Delivery Mechanisms for Prospective Information Needs: An Analysis of Attention in Mobile Users

Real-time summarization systems that monitor document streams to identify relevant content have a few options for delivering system updates to users. In a mobile context, systems could send push notifications to users' mobile devices, hoping to grab their attention immediately. Alternatively, systems could silently deposit updates into "inboxes" that users can access at their leisure. We refer to these mechanisms as push-based vs. pull-based, and present a two-year contrastive study that attempts to understand the effects of the delivery mechanism on mobile user behavior, in the context of the TREC Real-Time Summarization Tracks. Through a cluster analysis, we are able to identify three distinct and coherent patterns of behavior. As expected, we find that users are likely to ignore push notifications, but for those updates that users do pay attention to, content is consumed within a short amount of time. Interestingly, users bombarded with push notifications are less likely to consume updates on their own initiative and less likely to engage in long reading sessions---which is a common pattern for users who pull content from their inboxes. We characterize users as exhibiting "eager" or "apathetic" information consumption behavior as an explanation of these observations, and attempt to operationalize our findings into design recommendations.