A case study in the development of a speech-based car cellular phone is presented. Specifically, the structure of human-machine speech dialogues was investigated in an iterative usability engineering process consisting of three phases. The first phase included a laboratory evaluation of an initial user interface design concept using a simple demonstration program. In the second phase, some recommendations were implemented in a partial prototype that included the speech recognition technology. This prototype went through a formal field usability test in real driving conditions. Finally, in the third phase, a fully operational product was again tested with human participants in driving conditions. Findings indicated that the iterative process was converging: less usability problems were reported in each phase. The implications of iterative usability engineering approaches in situations with changing underlying technology during the development of consumer products are discussed.

Consumer product development, Human-centered design, Speech-based user interface, Usability engineering
International Journal of Industrial Engineering : Theory Applications and Practice
Department of Psychology

Parush, A. (2004). Usability engineering case study of a speech-operated car phone. International Journal of Industrial Engineering : Theory Applications and Practice, 11(3), 221–230.