Using Field Experiments to Evaluate Mobile Guides

This paper discusses the experimental evaluation of locationbased services, such as mobile guides, in the field. It identifies advantages and disadvantages of using such field experiments over and against other evaluation methods. We then describe a specific method of running field experiments that we have found to be useful. The use of various evaluation measures, tools and scales is then discussed, based on our experiences with them. These include timings, errors, perceived workload, distance travelled and percentage preferred walking speed (PPWS).