UC Berkeley

Dynamic visualizations can strengthen chemistry instruction by illustrating atomic level phenomena. Visualizations can help students add ideas about unseen phenomena involving atomic particles. They allow students to interact with phenomena that cannot be investigated in hands-on laboratories. Connecting dynamic, atomic representations with associated observable phenomena and symbolic representations has the potential to increase the coherence and comprehensiveness of student understanding.

Consistent with the knowledge integration framework, students enter chemistry courses with multiple non-normative ideas about chemical reactions. Following the knowledge integration framework, an inquiry project entitled Hydrogen Fuel Cell Cars engaged students in making predictions, exploring new ideas, distinguishing among ideas, and reflecting while connecting atomic interactions to everyday issues such as cars and fuel. To add normative ideas, a dynamic visualization that shows bond breaking and formation during hydrogen combustion was embedded in the unit. Using an iterative design process, a series of studies compared four approaches to distinguishing ideas: unguided exploration of the visualization, generating drawings of the sequence of events in the visualization, critiquing sequences of drawings attributed to a peer, and selecting among alternatives sequences. Progress was assessed using assessments that required students to articulate coherent accounts of chemical reactions.

The dissertation describes the design and development of the instruction, reports on a series of comparison studies conducted in typical middle schools that compare student performance in each of the four conditions: exploration, drawing, critique, and selection. The results reveal that visualizations can be deceptively clear so students may ignore important details when exploring a visualization. When learners generate, select, or critique drawings of atomic interactions, they recognize gaps in their knowledge, develop criteria for distinguishing among ideas, and increase in ability to select normative ideas. The dissertation demonstrates the importance of encouraging students to distinguish ideas when learning with visualizations. It suggests design principles for creating instructions featuring visualizations that can succeed in typical classrooms.