Endorsing and Rejecting Scientific Claims: The Role of Evidence in Scientific Discourse

from a “rhetoric of conclusions ” to a social process of knowledge construction via scientific argumentation. This emphasis on argument recasts the role of evidence and data in scientific classrooms: rather than being used to demon-strate scientific principles, it is the grounds on which claims are warranted. This understanding of science has launched curricula and research programs that are aimed at improv-ing students ’ abilities to coordinate theory and evidence in scientific argumentation. In this paper, I examine a tran-script of scientific discourse, exploring the rules by which participants in the discourse endorse or reject scientific claims. I appeal for a more nuanced understanding of di-rect evidence as one of many criteria by which scientific claims are evaluated, and that evidence, at times, is incom-mensurable with other criteria. Science is Argument Our understanding of science over the past decades has shifted to an appreciation of science as a social process of knowledge construction where claims are “grounded through the process of argument – relating the imaginative conjectures of scientists to the evidence available ” (Driver, Newton and Osborne, 2000, p. 295). This view of science as argument has led to investigations of the ways in which students provide warrants and backings for claims whe