Toulmin's model of argument has been used by researchers as a theoretical perspective on argument and as a methodological tool for analysing episodes of oral argumentation in school science. An adaptation of Toulmin's Argument Pattern (TAP) has also informed a professional development programme for teachers. Research on the impact of the programme on pedagogic practice shows that Toulmin-based materials are advantageous in helping teachers to conceptualize argument and model it for students. A framework developed from TAP can also be used to evaluate student outcomes when using argumentation software. However, a focus on the process of argumentation limits any consideration of the content and quality of evidence. (Contains 1 table, 4 figures and 1 note.)