We try to realize the idea that concepts first and calculation later. During the last successive two academic years, we adopted the format of pencil-paper test in both the midterm and final examinations. Students' performance as the data base was collected and analyzed to figure out their understanding about direct-circuit current. We see that the intuitive ideas still persisted after the classroom discussion and end-of-chapter homework exercises. The scores of the exams are not just numbers, but also serve as a window and offer an opportunity to better understand our students' cognitive dynamics. We also expect to probe some epistemological beliefs that are related to their self-awareness, implicitly but deeply affect their learning outcomes.