Investigating and Improving Student Understanding of Conductors and Insulators

Concepts involving conductors and insulators are challenging at all levels of instruction. Here, we summarized an investigation of the difficulties that introductory students have pertaining to the charging of conductors and insulators and how that research was used as a resource to develop, validate, and evaluate a conceptual tutorial on this challenging topic. The tutorial uses guided inquiry-based teaching–learning sequences and focuses on helping students develop conceptual understanding of charging conductors and insulators using concrete examples. At a large university in the US, we first evaluated whether there was any statistically significant difference on the pretest (before college instruction) between the performance of students who had any high school physics instruction and those who did not on relevant questions. Then, we compared the performance of introductory physics students in the experimental group who engaged with the tutorial and the control group who did not engage with the tutorial and only had traditional, lecture-based instruction. Our analysis shows large improvements from pre- to post-tests (i.e., from before to after instruction) for the tutorial group and large gaps in post-test scores between the nontutorial and tutorial groups.