This paper re-validates middle school students' learning progression of the concept of buoyancy (Gao et al., 2020) by using two-time point data. The previous study developed a four-level learning progression based on data collected at a single time point using cross-sectional design. This single-time-point model of learning progression calls for a…

We applied latent class analysis and the rule space model to verify the cumulative characteristic of conceptual change by developing a learning progression for buoyancy. For this study, we first abstracted seven attributes of buoyancy and then developed a hypothesized learning progression for buoyancy. A 14-item buoyancy instrument was…