Analysis of misconceptions of Engineering Technology students about electricity and circuits: A mixed methods study.

摘要

Effective instruction in Engineering and Technology requires knowledge of how students understand or misunderstand key concepts in these disciplines. This dissertation focuses on the analysis of students' misconceptions about electricity and circuits. It presents a synthesis of methods from educational research and cognitive psychology applied to a population of Electrical Engineering Technology students.;Incorrect mental models, deeply rooted in everyday experience, can significantly affect student learning. Evidence suggests that students who learn new material may already have some understanding and preconceptions about presented-in-classroom concepts. Misconceptions about electricity of freshmen and sophomores were analyzed and compared to the misconceptions of seniors. The goals of this dissertation targeted: (1) investigating the correlation between student academic success (grades) and their misconceptions, and (2) understanding how student mental models and misconceptions change with increasing levels of competency and expertise during the students' progression from the freshman to senior level. Twenty two seniors and twenty novices (freshmen and first-semester sophomores) enrolled in the Electrical Engineering Technology program at Purdue University participated in the present study. The study design employed a mixed-methods methodology, including quantitative and qualitative phases. The quantitative phase conducted a correlational investigation; the qualitative phase was built on grounded theory principles. In the quantitative stage, all 42 participants responded to 29 questions from the DIRECT version 1.0 Concept Inventory (see Engelhardt & Beichner, 2004). In the qualitative stage 16 out of 42 students (8 novices and 8 seniors) explained aloud their incorrect responses to the DIRECT CI, and responded to four open-ended questions about general understanding of electricity. Students' interviews were analyzed using open coding. The findings showed that correlation between grades and misconceptions was statistically significant for both novice and senior groups. The two most interesting and unexpected results were: (1) in the novice group correlation between grades and misconceptions was stronger than in the senior group. Incorrect understanding of electricity in the senior group can apparently be disguised by a well-developed technical vocabulary. Notably, even the brightest high-GPA students evidenced numerous mistaken beliefs; (2) despite the improvement in understanding of electricity; seniors had more misconceptions (and were more confused) than novices about physical and fundamental electrical concepts, such as `charge' or `electrical field'. Also, two widespread among the students' analogies were detected: (1) water flow and electrical current, and (2) electricity is a "substance-that-can-be-used-up." These analogies were identified as the most popular mental models, and they continued to be frequently used as novices progressed to senior level.