Evaluating the Icon-Based Interface for Words Strategy, an Augmentative Communication System

Abstract

The purpose of this paper is to present an evaluation of the icon-based interface employed in Words Strategy, an augmentative communication system used by speech impaired and nonspeaking individuals. Words Strategy is a software system implemented in the Prentke Romich Touchtalker, a special purpose computer which allows individuals to enter entire sentences with very few keystrokes, and which provides synthetic speech output of those sentences. The system has been criticized because of the long training period required for mastery, and because its use of multi-meaning icons might impose a severe memory load on the user (Light et al., 1988). The two studies presented derived a learning curve for Words Strategy and investigated the relearning of the system six months after initial training. The Touchtalker keyboard layout was also evaluated. Results indicated that the assignment of multiple meanings to an icon did not create a problem; in fact, it enhanced performance. In addition, relearning of the icon associations occurred rapidly, generally within one trial. The implications of the data for redesign of the Touchtalker keyboard are discussed.