Graphical user interfaces and visually disabled users

摘要

From February 1992 until the end of 1993, the authors ((IPO) Institute for Perception Research) participated in a European ((TIDE) Technology Initiative for Disabled and Elderly) project which addressed the problem arising for visually disabled computer-users from the growing use of Graphical User Interfaces (GUIs). With the authors' project partners (Frank Audiodata, the Nottingham Polytechnic, and Sensory Visionaid), they developed and evaluated a system which allows visually disabled users of computers to continue using computers, despite the fact that the workplace must, for reasons of uniformity, service, system management, etc., adapt to the use of GUI's. In principle, two approaches to dealing with the aforementioned problem are possible. Firstly, a software bridge can be made to transfer system information to and from a user-specific I/O device (e.g., a Braille line and keyboard). Secondly, a hardware solution can be created, consisting of a second computer which taps the video output and feeds back information via the keyboard and/or mouse connection. Each solution has its own advantages and disadvantages. However, both approaches require modeling of the GUI information in order to transfer data efficiently between the GUI and the user-specific I/O device. In the authors' project, the hardware approach was chosen, the pros and cons of which are discussed here. The GUI modeling proved feasible and is incorporated in the VISA-comp system. The authors' usability evaluation showed that visually disabled users can have access to a GUI, although it takes them about three times longer than sighted users.