Wizard of Oz (WOz) testing has shown promise as an effective way to test location-enhanced applications. However, it is challenging to conduct a location-based WOz test because of the dynamic nature of target settings in the field. In particular, continuous location tracking, a major task in such a test, requires a wizard to frequently update a user's location to simulate a location system. This imposes a heavy task load on a wizard. To ease wizards' tasks for location tracking, we designed two techniques, Directional Crossing and Steering, and conducted a field experiment to investigate the performance of the two techniques. A quantitative analysis shows that Directional Crossing and Steering significantly lowered a wizard's task load for location tracking without sacrificing accuracy. Author Keywords Wizard of Oz, location-enhanced application, field study. ACM Classification Keywords I.3.6 [Methodology and Techniques]: Interaction techniques
Yang Li, Evan Welbourne, James A. Landay