In this paper we describe our project in which we study design options for a GPS-based navigation aid for elderly with beginning dementia. In a user centered approach we first studied problems of the target group. Results were used in the design of a WoZ prototype. The method proved to work very well in designing a prototype that is tuned to the needs of the user. This prototype was used in experiments in which we studied the performance of landmark vs. left right instructions in navigation. We found that landmark based instructions resulted in less errors and less hesitation with the users.
F. N. Hagethorn, Ben J. A. Kröse, P. de Greef