ABSTRACT

Technological advances and increased computing power have led to many new assistive devices in recent years, for people who are blind or who have low

CONTENTS

Introduction ......................................................................................................... 133 Know the Target Population .............................................................................. 135 Performance Measures ....................................................................................... 136

Reaching the Destination .............................................................................. 137 Number of Deviations from Intended Route (Path Confusions) ............ 137 Recovery from Route Deviations ................................................................. 137 Time to Reach a Destination ......................................................................... 137 Distance Measures.......................................................................................... 138 Evaluating Spatial Learning ......................................................................... 138

Special Measures for Evaluating Devices for Safety and Wayfinding at Street Crossings ................................................................................................... 139 Choosing an Appropriate Baseline Measure ................................................... 144 Designing Unbiased Evaluations ...................................................................... 146 Selecting Participants.......................................................................................... 148 Distractions and Cognitive Demands While Traveling ................................. 151 Subjective Measures: Efficacy and Performance Evaluated by Participants ..................................................................................................... 151

Evaluation through Questions and Rating Scales ..................................... 153 Evaluation Using Open-Ended Questions ................................................. 154 Evaluation Using Focus Groups .................................................................. 155 Evaluating Performance of the Technology ............................................... 156

Summary .............................................................................................................. 157 References ............................................................................................................. 157

vision. Unfortunately, many of those designed to help travelers who are visually impaired navigate and travel safely have not been widely adopted. This chapter addresses the evaluation of assistive devices for travel and wayfinding, with the hope that concrete examples of good experimental procedures and a better understanding of the target audience, can assist in the development of devices that are user-friendly to a wide range of travelers who are visually impaired, and which provide positive benefits to independent travel.