The media appropriateness theory states that people choose certain medium according to how appropriate this medium is able to achieve their goals. Based on this theory, this study postulated that people used electronic mail(e-mail) and telephone for different purposes. More specifically, this study predicted that the choice of the appropriate medium would be affected by three variables, (1)the usage characteristics of the media; (2)the context in which the media were chosen; (3)the richness and social presence levels of the media.
250 questionnaires were distributed to the students in the universities in Taiwan, and 212 valid pieces were returned to the researcher. The results have proved the differences of the richness and of social presence levels between telephone and e-mail. In general, this study found that respondents used telephone rather than e-mail to discuss complicated issues and with people of closer, intimate relationships, since they believe telephone is more suitable than e-mail for the communications which need immediate feedbacks.