Lilsys

As communications systems increasingly gather and propagate information about people's reachability or ``presence'', users need better tools to minimize undesired interruptions while allowing desired ones. We review the salient elements of presence and availability that people use when initiating face-to-face communication. We discuss problems with current strategies for managing one's availability in telecommunication media. We describe a prototype system called Lilsys which passively collects availability cues gathered from users' actions and environment using ambient sensors and provides machine inferencing of unavailability. We discuss observations and design implications from deploying Lilsys.