The National Research Council emphasizes the centrality of discourse and practices associated with constructing, evaluating, and using scientific explanations. These expectations increase already daunting challenges for those who teach science at the elementary school level. This study followed a multiparticipant case study approach examining prospective elementary teachers' self-reports of teaching science as argument. Findings yield that the presence of opportunities for physical experimentation with firsthand data during science instruction helped participants increase their emphasis on evidence-based explanations. Participants also viewed science talks as essential and fundamental for engaging students in evidence-based explanations. Finally, participants demonstrated attention to scientific subject matter. These findings are discussed in terms of their implications for teacher education.