This study had two purposes. The first purpose was to investigate the effect of a unit based on a theoretical model of argumentation (Toulmin’s) on college students’ argumentative writing. The second purpose was to examine the effects of the proposed unit on the participants’ writing apprehension and writing self-efficacy. One hundred and forty three (143) second year college students in a faculty of education, English majors were assigned randomly into one of two conditions. Both groups engaged in pretest and posttest measures of writing performance, writing apprehension and writing self-efficacy. Control group participants were taught using the regular writing course while the experimental group participants were taught the regular course in addition to the proposed instructional unit. The results of the study showed that experimental group participants showed significant improvement in their argumentative writing performance. In addition, it was found that writing apprehension and writing self-efficacy had no influence over writing performance. Furthermore, the results suggested that writing self-efficacy was what influenced writing apprehension and not vice versa.

Journal of Psychological and Educational Research, 2004, 19, 1-42.