This paper proposes the inclusion of travel and mobility in the usability metrics of web design. Hypertext design and usability has traditionally concentrated upon navigation and/or orientation. The notion of travel extends navigation and orientation to include environment, mobility and the purpose of the travel task. The presence of travel aids are important for all users, but particularly so for those with a visual impairment. This paper presents the ground work for including travel into web design and usability metrics by presenting a framework for identifying travel objects and registering them as either cues to aid travel or obstacles that hinder travel for visually impaired users. The aim is to maximise cues and minimise obstacles to give high mobility; measured by the mobility index. This framework is based upon a model of real world travel by both sighted and visually impaired people, where travel objects are used for orientation, navigation, route planning and survey knowledg...
Carole A. Goble, Simon Harper, Robert Stevens