Although much has been discussed about argumentation in various academic fields, prior attempts to develop teaching method for argumentative skills have been inconclusive. The purpose of this paper is to investigate the process of how inexperienced students acquire argumentative skills in a community of practice, and to provide an instructional approach regarding characteristics of learners obtained by the experiments. 20 freshmen participated a four-week debate training and a series of tests. After the session, most of the 18 subordinate argumentative skills which were set for analytic schema were improved, compared with the pretest. However, skills such as “Reasonableness of grounds” “Numbering” “Labeling” were revealed difficult to learn without formal instructions. Further analysis of patterning arguments clarifies underperformance of some particular types of the participants. By discussing these results, the prospects of argumentative education for Japanese students are explored.
