Context-aware applications are computer systems that make use of implicitly gathered information, such as a person's identity, location, and activity. This is in contrast to traditional computer systems that require explicit user interaction for all input.
This work is addressing two different but related problems. The first is organizing and managing the sensors, data, and services in a meaningful way. The second is doing all of this in a privacy-sensitive manner that provides end-users with greater control and feedback over what information is being collected about them and how that information is being used.
The main abstraction we are developing is InfoSpace. InfoSpaces are repositories of context information designed to be analogous to web sites. That is, in the same way that many people create and manage personal web sites, they would create and manage personal InfoSpaces. While a person would only have one logical InfoSpace, they may have several InfoSpaces that physically reside on multiple devices, thus providing people with high availability even when mobile.
However, systems that collect highly personal information like this are always strongly criticized because of potential privacy threats. To address these legitimate concerns, we are integrating several privacy mechanisms, including basic access control to limit queries, the option to return intentionally ambiguous results, privacy tags for specifying privacy preferences on data that flows from one InfoSpace to another, and user interfaces for helping end-users understand who has been accessing their data.