Arguments are important to the construction of scientific knowledge and practices including the development of skills and tools for assessing that knowledge. Whereas research on arguments continues to accumulate, there is little evidence that this work focuses on the development of both instructional and assessment tools to support students in using empirically verifiable data and make connections of data to claims about natural phenomena. In this dissertation study, I use a modified version of Toulmin's (1958) model of argument analysis to examine the kinds of Data and Warrants, and sometimes Backing (elements of argument) students use to support the Claims they make about matter and energy (e.g. see Jin & Anderson, in preparation) in their oral arguments about the Carbon Transforming Processes (CTPs) of Tree Growing (TG), Flame Burning (FB), and Car Running (CR).

Findings from this study suggest that students use different kinds of elements to support their Claims. In particular, more sophisticated responses tend to be characterized by those elements that appeal to scientific principles. However, less sophisticated responses tend to include elements that are, for example, analogical, and/or tautological, as well as personal beliefs to support the Claims made about these processes, and thus tend toward force-dynamic reasoning (Pinker, 2007). Implications for teaching, learning and research in science education are included.