A location representation for generating descriptive walking directions

An expressive representation for location is an important component in many applications. However, while many location-aware applications can reason about space at the level of coordinates and containment relationships, they have no way to express the semantics that define how a particular space is used. We present Lair, an ontology that addresses this problem by modeling both the geographical relationships between spaces as well as the functional purpose of a given space. We describe how Lair was used to create an application that produces walking directions comparable to those given by a person, and a pilot study that evaluated the quality of these directions. We also describe how Lair can be used to evaluate other intelligent user interfaces.