R D Stevens

An approach to the evaluation of assistive technology

A valid criticism of may innovations in assistive technology is that they have not been evaluated. However. there are obstacles which make this form of technology difficult to evaluate according to conventional paradigms. The reasons behind this are discussed. A particular evaluation which endeavoured to circumvent those problems is described. The item evaluated was Matllta/k, a program to make mathematics accessible to blind people.

Mathtalk: the design of an interface for reading algebra using speech

The problems that a visually disabled person has with reading, writing and manipulating standard algebra notation are characterized in terms of speed, control and external memory. The Mathtalk program has been developed to enable the listener to read algebra notation in a quick and active manner, that overcomes some of these problems. Prosody has been added to the synthetic voice output to resolve grouping ambiguities, decrease mental workload and improve memory for the presented notation. Browsing functions and the associated command language allow the listening reader to shift his or her attention to any part of an expression. To make most effective use of the speed and control afforded by Mathtalk, an audio glance is provided that should allow planning of the reading process. The development and evaluation of Mathtalk has led to the proposal of a set of design principles that should facilitate the production of other, similar user interfaces for the reading of structured information. Further work includes the development of Mathtalk in the TIDE Maths project. As well as reading, the problems of writing and manipulation need to be tackled.