General chemistry students’ resource activation patterns in a titration curve interpretation task

Abstract

How students read graphical information in chemistry depends not only on what a graph displays but on which features they treat as meaningful and what knowledge those features activate. This study uses the cognitive resources perspective as framing to examine how undergraduate general chemistry students reason about titration curves in a preservative selection task involving juice stability and microbial growth. Twelve second-semester general chemistry students participated in think-aloud interviews while selecting a preservative based on graphical evidence. Analysis identified two distinct resource activation patterns. For six students, reasoning was organized around discrete pH values, drawing on part-for-whole and comparing resources productive in stoichiometric contexts. For five students, reasoning centered on slope and rate of change, with resistance-to-change resources linked functionally to preservation goals. One student activated both patterns. Although all approaches drew on productive existing knowledge and could yield correct selections, they reflected qualitatively different activation patterns. These findings indicate that variation in titration curve interpretation reflects differential activation of existing resources shaped by perceptual salience and task framing, with implications for how instruction might support students in activating slope- and resistance-based reasoning in graphical contexts.