Coding to analyze students' critical thinking

Using a problem developed from Guinotte et al. (pp 141-146), we illustrate a research approach to determine the effectiveness of inquiry-based instruction on students' understanding. Two research studies, one in biology (Udovic et al. 2002) and one in chemistry (Wright et al. 1998), influenced our thinking about how to proceed. Both are exemplary studies that examined the impact of active learning and cooperative groups on student learning by comparing reformed courses to traditional existing courses. The studies coded and analyzed students' written and oral responses to determine their understanding. Udovic et al. (2002) concluded that students in the reformed course showed significant gains in conceptual learning, scientific reasoning, and attitudes about science; Wright et al. (1998) concluded that students in the reformed course demonstrated higher-level critical thinking skills in oral assessments given by faculty external to the course. Human-induced changes in seawater chemistry, as illustrated in Guinotte et al., is a newly emerging topic in biology and is connected to larger issues surrounding global climate change. The main concept of the paper is appropriate for a unit on carbon cycling designed to expand students' understanding of carbon fluxes in both marine and terrestrial systems. For students not familiar with marine systems, it may be counterintuitive to relate addition of carbon to oceans with degradation of calcium carbonate-based skeletal structures such as corals. A common preconception among students is that as more carbon goes into the ocean, more calcium carbonate becomes available to build the skeletons of corals and other marine organisms.