The uses of Toulmin: the value of an explicit model of argument for academic and working engineers

This paper presents a case study of an engineering writer learning to use Toulmin logic as a strategy for writing. Before the case, Toulmin logic is explained in terms of two concepts: force and criteria, and elements of argument. Then, a pedagogical approach and several classroom exercises are explained to illustrate the ways in which Toulmin logic has been introduced to the students. Finally, the engineer´s writing is analyzed through four iterations. His revisions reveal that he has absorbed the ideas of tightening the warranting of claims to though unconsciously. These results suggest that Toulmin´s model is useful not only for helping writers to improve their organization, but also for helping them shape the ideas themselves.