ABSTRACT
Four different platforms were compared in a task of exploring an angular stimulus and reporting its value. The angle was explored visually, tangibly as raised fine-grit sandpaper, or on a touch-screen with a frictional or vibratory signal. All platforms produced highly accurate angle judgments. Differences were found, however, in exploration time, with vision fastest as expected, followed by tangible, vibration, and friction. Relative to the tangible display, touch-screens evidenced greater noise in the perceived angular value, with a particular disadvantage for friction. The latter must be interpreted in the context of a first-generation display and a rapidly advancing technology. On the whole, the results point both to promise and barriers in the use of refreshable graphical displays for blind users.
