DESTINATION DESCRIPTIONS IN URBAN ENVIRONMENTS PhD THESIS

An important difference exists between the way humans communicate route knowledge and the turn-by-turn route directions provided by the majority of current navigation services. Navigation services present route directions with the same amount of detail regardless the route segment’s significance in the instructions, user’s distance from the destination, and finally the level of user’s familiarity with particular parts of the environment. A significant feature of human-generated route directions provided to people is the hierarchical communication of route knowledge. References are made to a simplified structure of the environment. Communication partners exchange route directions assuming a shared knowledge of the coarse environment’s structure. Such destination descriptions provide an increased amount of detail as the description approaches the proximity of the destination of the route. The research presented in this thesis aims to improve the communication of navigation information by presenting a formal model enabling the selection of references for destination descriptions. The model is based on the analysis of the reflection of the structure of the urban environment in destination descriptions provided by locals. In such spatial communication, common knowledge of the coarse structure of the city is inferred. The main contribution of this thesis is the analysis of the reflection of the structure of an urban environment in the route directions exchanged between people with at least coarse knowledge of the environment, and the formalization of these principles in a computational model that enables automated selection of referents for destination descriptions. In the approach presented, the environmental elements of the city structure are hierarchically integrated together with a model of the communication processes underlying the creation of destination descriptions . Automated creation of directions with a variable level of detail will improve the ability to reflect the alteration of local conditions. The resulting route directions are usually shorter than those created by current navigation services, and thus lower the cognitive workload of the wayfinder. The benefactors of such a system are wayfinders frequently traveling to unfamiliar destinations in partially-known urban environments, such as the police, emergency management and tourism services, but also locals—everyday users of Web based navigation portals.