ABSTRACT
Location is one of the most important components of user context (Schilit et al., 1999). In addition to being useful in its own right, location information can also be used to infer additional pieces of context, such as user activity, mode of transportation, and social relationship. For example, spending time at a gym is indicative of exercising, changing location at a speed of 65 miles per hour is indicative of driving, and driving someone every morning to and from work is indicative of a close relationship. We refer the reader to Chapter 8 for an in-depth discussion on the use of contextual information in ubicomp.
