DyPERS, 'Dynamic Personal Enhanced Reality System', is a wearable system which uses augmented reality and computer vision to autonomously retrieve 'media memories' based on associations with real objects the user encounters. These are evoked as audio and video clips taken by the user and overlayed on top of real objects the user looks at. The user's visual and auditory scene is stored in real-time by the system (upon request) and is then associated (by user input) with a snap shot of a visual object. The object acts as a key which is detected by a real-time vision system when it is in view, triggering DyPERS to playback the appropriate audio-visual sequence. The vision system is a probabilistic algorithm which is capable of discriminating between hundreds of everyday objects under varying viewing conditions (lighting, pose, etc.). The record-and-associate paradigm of the system has many potential applications. Results on the use of the system in a museum tour scenario are described.

\Typical " computer users struggle to organize and nd their own electronic documents, manage their schedules and correspondence, and lter an ever increasing deluge of information. The process is made worse as users are forced to combine the disparate features of many applications to achieve these tasks. These problems suggest that our current software systems are ill-equipped to handle the demands of the typical computer user. Research has shown that common desktop environments (such asthe Macintosh \desktop") are often badly tted to users ' needs. In an attempt to do better we have reduced \information management " to a few simple and unifying concepts and created \Lifestreams. " Lifestreams is a software architecture based on a simple data structure, a time-ordered stream of documents, that can be manipulated with a small numberofpowerful operators to locate, organize, summarize and monitor information. In this dissertation we rst provide motivation for Lifestreams. We then present the model and discuss the development of our research prototype. Our prototype realizes many of the system's de ning features and has allowed us to experiment with the model's key ideas with actual users (of di ering levels of computer experience) over the course of its development. Results from its use suggest that Lifestreams is an e ective software architecture for managing common computer tasks; its simple organizational storage system (the stream) combined with a small number of powerful operators provides a uni ed framework that subsumes many separate desktop applications to accomplish and handle the most common personal communication, reminding, and storage and retrieval tasks. In addition, Lifestreams suggests valuable new capabilities for electronic systems.