Focusing on the quality of reasoning in students’ persuasive writing: Moving beyond argumentative form to substance

In studies investigating students' essays, the persuasiveness of the ideas presented is often measured by considering standard elements of argumentation established by Stephen Toulmin. When all of these elements can be identified in a student's argumentative essay, the essay is usually considered to have achieved good argumentative form, and thereby satisfactory persuasiveness. However, such an assessment is not necessarily a judgment of the actual quality of the reasoning, such as the argument's relevance, accuracy and structural logic. In the present case study, the arguments, counterarguments and rebuttals of six essays of exemplary argumentative form isolated from a group of 125 high school students in Hong Kong are analyzed for their quality of reasoning. This evaluation of quality was arrived at via questionnaire responses from 46 doctoral students who rated the arguments of the students. Findings revealed several patterns of inadequacies in the reasoning of the six cases, which may otherwise have been rated highly for their argumentative form by the standards of a modified Toulmin model. For example, although each of the six essays included sufficient argumentative form, i.e., claims, counterarguments and rebuttals along with associated supporting reasons, sometimes the reasoning was deemed weak or irrelevant. In other cases, rebuttal claims were logically unaligned to counterarguments. These faulty patterns expose the need to bring greater attention to the quality of reasoning in students' persuasive writing. Accordingly, a new set of scoring rubrics that encompasses both argumentative form and quality is proposed.