| Summary: | 博士 === 國立彰化師範大學 === 科學教育研究所 === 88 === The purpose of this study was to investigate a class of senior high students'' explanations of physical phenomena by means of content and epistemological approaches. First, in content approach, three topics, including image reflection, the refraction of water and light, and phenomena in diffraction, were presented to the students as open-ended questions before instruction. All the students were asked to express and explain their opinions of these physical phenomena. Second, in epistemological approach, a semi-structured questionnaire consisting of different models of explanation was developed, according to the students'' responses in the previous open-ended questions and the teacher''s explanations during in instruction. Third, the students were asked not only to evaluate the acceptability of these explanations but also to give reasons. The qualitative method was used to analyze the students'' responses in pencil-and-paper tests and interviews. This study focused on the following research questions: (a) What were the students'' conceptual frameworks for explaining phenomena in mirror image formation, refraction, and diffraction? (b) How did the students use and shift their conceptual frameworks in different situations? (c) What was the students'' levels of agreement with these various models of explanation? and (d) What were the roles of students'' conceptual frameworks and epistemological approaches in understanding of concepts?
It was revealed that the senior high students employed various ways to explain physical phenomena in mirror image formation, refraction, and diffraction. For mirror image formation, the students tended to be influenced by written words, symmetric diagrams, or shape changing on the mirror surface''s curve. For refraction, many students argued there was no refraction in a sink of water even it was shallow at one side and deep at the other side, because refraction happened between different media only. For diffraction, the students preferred to think that diffraction was the result of the interaction between incident-waves and obstacles/media. It emerged that students'' frameworks were coherent, situation-fixed, or hard to transfer in different situations. On the other hand, students'' epistemology approaches showed that most students tended to accept diagrammatic, simple formulated, and easy imagined dynamic models of explanation. In addition, the students also paid attention to the reasonableness of explanations, especially relating explanations to his own life experiences, asking if the explanation really explains the phenomena, and being able to apply the explanations to every key situations. Generally speaking, most senior high students felt difficult to explain and evaluate phenomena in physics learning, because such demands were quite rare in traditional measurements in high schools.
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