Science teachers usually view students' uncertainty as a barrier to overcome, a negative experience to be avoided, a deficiency in need of remedy. Building on the theory of deep learning in science as a generative and sensemaking process, the purpose of this design‐based study is to identify tactics for teachers to manage their students' epistemic uncertainty as a pedagogical resource to develop student conceptual understanding during whole‐class discussion. Classroom observations of whole‐class discussion were collected from six teachers' classes ranging from third to eighth grade. A total of 18 whole‐class discussions were collected, transcribed, and analyzed. A storyline talk to manage uncertainty during whole‐class discussion was developed and consisted of three stages: (1) Raise epistemic uncertainty through creating ambiguous conditions; (2) Maintain epistemic uncertainty through preventing immature disclosure and discussing alternative explanations or conflicting ideas; and (3) Reduce epistemic uncertainty through making coherent connections among current uncertainty, prior knowledge, and familiar phenomena. Seven nuanced tactics used by teachers to achieve each stage of uncertainty management were identified. The results suggest that managing uncertainty goes beyond asking questions and problematizing phenomena. When engaging students in storyline‐based whole‐class discussion, teachers should focus on one specific uncertainty and establish a coherent, consistent storyline that raises, maintains, and reduces student uncertainty to horizontally and vertically construct a collective knowledge among students. The horizontal nature occurs within a stage of management, and the vertical nature of a storyline talk is related to moving along from stage to stage. Through the storyline talk focusing on students' epistemic uncertainty, students can truly become agents in the learning process when the lesson is centered on and driven by students' uncertainty.

Argumentative writing advances students' understanding of scientific concepts, ability to communicate, and scientific literacy. However, it remains unclear which components of argumentative writing drive such advancement. Further, most studies on argumentative writing have focused on students majoring in science, rather than in the nonsciences. The purpose of this study was to determine which components of argumentative writing are predictors of academic achievement in a general chemistry course designed for nonscience majors. The participants included 163 undergraduates at a public university. The quality of argumentative writing was positively and significantly correlated with student academic achievement. Five components of argumentative writing were predictors of success on student achievement tests: accuracy of the claim, relationship between claim and question, relationship between claim and evidence, use of multiple modes to represent an argument, and the degree to which writing style aligns with the writing type desired. Therefore, results from this study would allow teachers to modify their approaches to emphasize components of argumentative writing that can predict student academic achievement. Results from open-ended questionnaires reveal that students viewed argumentative writing as a tool that improves their conceptual understanding, advances their epistemic understanding of an argument, and can be applied in their future careers. Implications of this pedagogy for chemistry teaching and learning are discussed.