BotMap: Non-Visual Panning and Zooming with an Actuated Tabletop Tangible Interface.

The development of novel shape-changing or actuated tabletop tangible interfaces opens new perspectives for the design of physical and dynamic maps, especially for visually impaired (VI) users. Such maps would allow non-visual haptic exploration with advanced functions, such as panning and zooming. In this study, we designed an actuated tangible tabletop interface, called BotMap, allowing the exploration of geographic data through non-visual panning and zooming. In BotMap, small robots represent landmarks and move to their correct position whenever the map is refreshed. Users can interact with the robots to retrieve the names of the landmarks they represent. We designed two interfaces, named Keyboard and Sliders, which enable users to pan and zoom. Two evaluations were conducted with, respectively, ten blindfolded and eight VI participants. Results show that both interfaces were usable, with a slight advantage for the Keyboard interface in terms of navigation performance and map comprehension, and that, even when many panning and zooming operations were required, VI participants were able to understand the maps. Most participants managed to accurately reconstruct maps after exploration. Finally, we observed three VI people using the system and performing a classical task consisting in finding the more appropriate itinerary for a journey.