Measuring Chemistry Students' Understandings of Multiple External Representations through Cluster Analysis

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An important aspect of learning about chemistry and related molecular sciences is developing abilities to interpret, generate, and communicate with representations of molecules, compounds, and the atoms and ions from which they are built. This Improving Undergraduate STEM Education (IUSE) research project will investigate how students interpret representations of four core chemistry concepts about which students often hold misconceptions (or alternative conceptions): electron structure and periodicity, molecular shape and polarity, bond energies and heats of reaction, and solution chemistry and precipitation reactions. Based on in-depth interviews with students, the research team will design four separate surveys to test students' understandings of these topics and to collect data from a national sample of undergraduate students enrolled in introductory chemistry courses. Once these tools have been developed and validated, the project team will also hold workshops to teach other chemistry instructors and chemistry education researchers how to best utilize the tools to assess students' understandings and provide baseline data upon which innovations in pedagogy and curriculum can ultimately be built. This exploratory research project will investigate the questions: (1) How do undergraduate students interpret multiple external representations of core chemistry concepts (MERC3s) within clinical interviews? What cognitive dissonance emerges, both within and across macroscopic, particulate, and symbolic domains? What alternative conceptions emerge? (2) How are reliability and validity best established when developing assessment items to measure cognitive dissonance and alternative conceptions? (3) What patterns in student reasoning about MERC3s are revealed through cluster analyses of responses to assessment items grounded in the students' cognitive dissonance and alternative conceptions about MERC3s? To ensure valid and reliable findings, the project team will use a sequential, mixed-methods research design and subject the data to rigorous psychometric testing, including cluster analysis. Cluster analyses will also be carried out with existing data sets regarding students' understanding of external representations of other core chemistry concepts. The use of cluster analyses to mine existing and new data sets will allow the research team to not only characterize students' understanding and use of representations of individual core concepts, but also characterize patterns in students' thinking that generalize across multiple core chemistry concepts. In addition, in years 2 and 4 of the project, chemistry education research capacity-building workshops will focus on teaching the advanced statistical techniques used in this research to a total of one hundred graduate students and postdoctoral scholars from across the country, further advancing the methodological repertoire within discipline-based education research.