Epistemic Levels in Argument: An Analysis of University Oceanography Students' Use of Evidence in Writing

The purpose of this paper is to examine university oceanography students' use of evidence in writing. Drawing from rhetorical studies of science writing and studies of argumentation in science education, a model for assessing students' arguments is proposed that considers the relative epistemic status of propositions comprising students' written texts. The study was conducted in an introductory university oceanography course in a large public university that utilized an interactive CD-ROM that provided geological data sets for student exploration of scientific questions. Student arguments were analyzed through a process of sorting propositions by epistemic level and identifying the explicit links within and across levels. These epistemic levels were defined by discipline-specific geological constructs from descriptions of data, to identification of features, to relational aspects of features, to theoretically formulated assertions. This form of argumentation analysis allowed for assessment of each student's writing on normative grounds and for comparisons across students' papers. Results show promise for the argumentation model as a methodological tool. The examination of epistemic status of knowledge claims provided ways of distinguishing the extent to which students adhered to the genre conventions specified by the task, i.e., providing evidentiary support for their argument concerning the theory of plate tectonics with real earth data. We draw on the findings to discuss ways argumentation theory can contribute to reform in science education.