In this study, we determined the effectiveness of the inquiry-based Itakura method for mediating alternate conceptions of preservice elementary teachers (N = 38) in an integrated mathematics, science, and technology methods course. We investigated alternate conceptions in the expansion of solids due to heating. There was a significant increase in participants' immediate learning gains after participating in the Itakura method. Retention data was gathered after 1, 2, and 3 months. After 3 months, retention levels dropped slightly, but not significantly. Responses revealed that the majority of the participants did not revert back to alternate conceptions after 3 months.