How do engineering students develop and reason with concepts of electricity within a project-based course?

摘要

Reform in science education has often emphasized task-based learning as an instructional method to improve student understanding and retention of concepts, and to promote the development of reasoning and problem-solving. Yet studies assessing student knowledge at the beginning and end of a task-based class show mixed results. Students in task-based science and technology courses may gain greater long-term retention of knowledge than their traditional counterparts, though immediate gains may be comparable. Curriculum developers and educators express concerns that the costs of developing and implementing task-based instruction may not justify the results. Yet the question of whether students learn more in a task-based setting than a traditional setting is difficult to answer without fully understanding how students learn in a task-based context. Toward this end, this study presents a tentative model of learning in task-based contexts.;A phenomenological perspective was employed to examine conceptions held by first-year undergraduate electrical engineering students around current, voltage, and resistance in simple and complex circuits. The study also examined how the students' prior knowledge interacted with their reasoning skills as these students engaged in a project based laboratory component of an introductory electrical engineering course. Students entering the course with low prior knowledge and high prior knowledge were selected for the study. Seven volunteered as participants and completed the study. Three were assessed as having low prior knowledge of electrical concepts, and four had high prior knowledge.;Subjects were interviewed near the beginning and after the end of an electrical engineering course that included a project-based laboratory. Interviews were analyzed for subject content knowledge. The subjects were observed performing in lab as they carried out various tasks using TekBots(TM) robotic kits. Dialogue between the subjects and others in the lab, including the researcher, was analyzed for evidence of reasoning skills and how the subjects used their knowledge and mental constructions when engaged in problem-solving.;Subjects displayed a wide range of conceptions, including alternative conceptions and conceptions that matched the target concepts as presented in the lecture section. As expected, students entering with low prior knowledge had many alternative conceptions and undeveloped ideas about electricity. Reasoning skills in lab were analyzed using a hierarchy presented by Driver et al. (1996). Subject reasoning ability, from phenomenon-based at the lowest to model-based at the highest, related less to prior knowledge of electrical concepts than it did to prior experience in mathematics classes. Thus one of the subjects who entered the class with little prior knowledge but high ability in mathematics was able to complete the tasks successfully, while another subject with high prior knowledge but low ability in math struggled through each of the tasks. These findings were used to refine a model of task-based learning that describes student knowledge and other factors brought to a task, the interaction between meaningful knowledge (that which is used spontaneously) and inert knowledge (that which is known, but is not applied spontaneously to the task), and questions how inert learning is activated to become meaningful.