Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.Includes bibliographical references (p. 113-116).The proliferation of mobile devices and their tendency to present information proactively has led to an increase in device generated interruptions experienced by users. These interruptions are not confined to a particular physical space and are omnipresent. One possible strategy to lower the perceived burden of these interruptions is to cluster non-time-sensitive interruptions and deliver them during a physical activity transition. Since a user is already "interrupting" the current activity to engage in a new activity, the user will be more receptive to an interruption at this moment. This work compares the user's receptivity to an interruption triggered by an activity transition against a randomly generated interruption. A mobile computer system detects an activity transition with the use of wireless accelerometers. The results demonstrate that using this strategy reduces the perceived burden of the interruption.by Joyce Ho.M.Eng