Unipolar Reasoning in Electricity: Developing a Digital Two-Tier Diagnostic Test

The purpose of this study was to develop a two-tier test to diagnose unipolar reasoning in electricity. Thus, at first, we built a questionnaire composed of four questions with two choices (True / False) with justification. The justification step is methodologically essential; it has allowed us to identify different categories of conceptual representations. Then we administered it to students (N = 100) in the Science education training program. The students’ answers were analyzed and used to create the choices for the two-tier questions. The two-tier questions allow the student to give his explanation if the choices presented do not conform to his representation. Finally, high school students (N = 25) completed an electronic version of the two-tier test to solicit their commentary. The majority was enthusiastic about their participation, despite the conceptual destabilization generated by completing this test.