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6404f97bd5c2c-teacher-education-in-physics
- Bu sahifa navigatsiya:
- Issues regarding the physics raised by the review
- Selected insights regarding the teaching and learning of physics from the review
- Selected instructional strategies from the review
Step 2: Review of the literature
. Teachers review the lit- erature on physics as well as physics learning relevant to their topic, and report on the main learning difficulties and instructional strategies. The process is guided by the course leaders, but teachers are asked to expand the suggested list of references. Results . The teachers were referred to the literature con- cerning the physics of surface charge distribution that causes the charges to flow, and to papers about innovative instruc- tional strategies in this topic. 38 Table I presents the original list of the teachers’ review of the literature as presented in conference I. After discussing the review of the literature, one of the teachers said: “You know what? The physics here is really complicated; it is nice to find out that people tackle the same problems everywhere.” Step 3: Diagnosis . Teachers design, administer, and ana- lyze a diagnostic questionnaire consisting of a few “simple” questions to examine students’ understanding. Results . Teachers usually compose examinations quite easily. However, the requirement to compose a diagnostic tool aimed at well-predefined goals was a new experience for many of them. Besides the enrichment of their subject matter knowledge and their pedagogical content knowledge, this stage of the workshop enriched their general pedagogical knowledge as well. Teachers raised questions and dwelled on issues unfamiliar to them such as: “What is a diagnostic tool? Does it have to be a questionnaire? What do we want to find out about students’ understanding? What do we mean by understanding?” According to the course-leader journal, fol- lowing the development of the diagnostic tool, the teachers suggested changing the plan of the course and asked for ad- ditional lectures supplying information about the ideas of “diagnosis” and “understanding.” The group designed questions focusing on the relationship between the electric field and current at different points of a dc circuit at different times. Since the electric field between the plates of a capacitor is studied in electrostatics and the charging of a capacitor is studied in dc circuits, the teachers decided to focus the questionnaire on the charging of a ca- pacitor. Table II presents the list of goals for the diagnostic questionnaire. TABLE I. Teachers’ present their review of the literature. 共a兲 Issues regarding the physics raised by the review 1. How does the current “know” how to split in a junction? 2. If the electric field exerts force on the charges, why is the drift velocity constant? 3. How do the charges know how to move in a meandering wire? 共b兲 Selected insights regarding the teaching and learning of physics from the review 1. How do students explain current flow in an open circuit and what can be done about it? 2. There is a gap between students’ conceptions of electric fields in the contexts of electrostatics and electric circuits: electric field in electrostatics is usually conceived by students as a force that causes charges to move, whereas in circuits, the electric field is conceived as a theoretical concept derived from the concept of the potential difference. Introducing the changes in the distribution of surface charges in electric circuits can help in bridging the gap. 3. The analysis of dc circuits is usually based on energy considerations without referring to the microscopic aspects inside and outside the circuit. 共c兲 Selected instructional strategies from the review 1. Murzin, for example, describes Drude’s model as an explanation of charge flow in a circuit and the relationship between j and E. 2. Parker and Chabay & Sherwood use the surface charge distribution to explain the electric field inside and outside a current-carrying conductor. 3. Jefimenko suggests interesting experiments demonstrating electric fields inside and outside meandering wires. RESEARCH-DESIGN MODEL FOR PROFESSIONAL¼ PHYS. REV. ST PHYS. EDUC. RES. 2, 020106 共2006兲 020106-5 Teacher Education in Physics 180 Since all the topics of the minimodules were based on the existing high-school physics syllabus, teachers were able to find quite easily the appropriate lesson for administering the diagnostic questionnaire. This choice of topics enabled them to incorporate research-based materials into their practice. The diagnostic questionnaire was administered to 93 high- school students studying A-level physics, after they had fin- ished electrostatics, dc circuits, and the charging and dis- charging of a capacitor. We asked the teachers to collect their students’ answers and to analyze the results cooperatively with their colleagues in the group and the mentor. Table III describes the diagnostic questionnaire, the analysis of the results, and representative statements of teachers regarding the data. The following are comments made by the teachers during the analysis of the data: 共i兲 Generally speaking, most of the students explain dc phenomena through energy-based considerations and not through forces on charges. 共ii兲 They relate electric fields in dc circuits to potential differences and not to charges. 共iii兲 Students have difficulties with transients: electric fields between the plates of a capacitor and in the wires of the circuit. 共iv兲 I imagined that all my students would know that after charging there is an electric field between the plates of a capacitor, I’m disappointed. 共v兲 You know what? A few students even said that this questionnaire caused them for the first time to think about dc circuits in terms of an electric field. Download 231.88 Kb. Do'stlaringiz bilan baham: |
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