2018 年 20 巻 2 号 p. 173-182
Children with severe/profound and multiple disabilities (SMD) have speech difficulties because of the severity of their mental and physical disabilities. To enable communication function in such patients, communication aids (CAs) with key guards for minimizing errors caused by involuntary movements are used. This article describes an action research to investigate the most accessible and usable combination of CAs and key guards for a 9-year-old participant with SMD. We prepared some key guards and assessed the percentage of correct key operations that occurred when the participant sent messages using three CAs. The key guards were developed using corrugated boards, and the depth and size of the keys were varied. Psychometric methods were utilized in individual training sessions for using these CAs with key guards, and the results revealed the most accessible key guard for minimizing the participant’s errors. When the participant used the key guards during class at his special school, one of the authors observed and adjusted the settings of the CA’s interface (e.g., key layouts and recorded voice messages) to enable easier use. Through these practices, the frequency of CA usage and number of output messages gradually increased. These results indicate that (1) the accessibility and usability of CAs and key guards should be assessed using psychometric methods and quantitative indexes and (2) the fitters of CAs should evaluate the accessibility and usability of CAs through qualitative evaluation (e.g., observation of behavior) and improve CA interfaces according to the users’ living situation and settings.
