The proportion of elderly in the United States is growing at a phenomenal rate, yet little of today’s information technology addresses the critical problems that arise as a result of this demographic shift.  The goard of this projects is to develop information technology that will address one such challenge:  that of enabling the elderly to remain living in their homes for as long as possible.   More specifically, we are designing and building a personal mobile robotic assistant for the monitoring and guidance of the daily activities of an elderly person.  This research includes the development of advanced techniques for flexibly reasoning about plans and monitoring their execution, the development of statistical algorithms for learning models of people’s daily activities, the design and evaluation of self-tailoring multi-modal interfaces that enable elderly people to interact easily with the robotic assistant, and the development of new sensor modalities to meet the needs of a mobile robot in an elder’s home.