探討科學解釋文字鷹架融合POE策略對概念改變與科學解釋能力影響之研究-以光學單元為例

Abstract

本研究的目的在探討預測-觀察-解釋( Predict-Observation- Explanation, POE )教學策略結合科學解釋文字鷹架，對八年級學生在光學概念改變與科學解釋能力的影響。此光學單元包括：光的直進、針孔成像與平面鏡的反射。研究對象為台灣北部公立國中兩班八年級學生一共57人，資料收集工具為活動學習單與光學概念二階層測驗卷。 本研究所用的POE課程是根據學生在光學常見的另有概念，設計出五個在POE概念改變活動。活動學習單分為有、無科學解釋文字鷹架兩種版本。科學解釋文字鷹架的目的在幫助學生進行觀察時，可以注意到使用證據的重要，並強調主張、證據與相關概念間的連結，以提高學生的解釋品質。POE活動進行時，實驗組使用融入科學解釋文字鷹架的學習單，控制組所用的學習單則反映傳統的POE活動設計，而兩組學習者在進行POE活動前已學過相關的光學課程。 研究結果發現：在概念學習成效上，無鷹架組別表現較融入科學解釋文字鷹架的組別稍好，但兩組差異未達顯著。在針孔成像主題中，未使用鷹架組別的概念學習成效顯著高於使用鷹架的組別，但學習單分析結果則顯示兩組進步人數相同；而平面鏡成像主題上，則是使用鷹架組別概念學習成效稍高，但兩組未達顯著，學習單的分析結果亦顯示概念進步人數為有鷹架組別稍多。科學解釋能力從主張、證據與支持三個要素進行評分，使用鷹架的組別在找出證據能力顯著優於無鷹架組別，但在提出主張與支持上無顯著差異，而學習單分析結果指出推理進步情形為有鷹架組別表現稍好。 本研究中的科學解釋文字鷹架對概念改變成效並無顯著影響。可能原因為POE活動與概念診斷測驗題目對應不夠精確，另外原因可能由於融入科學解釋文字鷹架造成學習者認知負荷過重，影響概念改變之成效。在科學解釋能力上，文字鷹架對學生提出解釋中的證據使用，幫助最大，但學生在提出連結主張與證據的支持，需要更多協助。

The purpose of this study is to explore the impact of conceptual change and scientific explanation skills on the eighth grade optics, by using POE ( Predict–Observation -Explanation )teaching strategies combining with scaffolds of scientific explanation. Topics of the instruction includes: light propagation, reflection, and image formation with pinhole and a plane mirror, participants involved 57, 8-9 grade students from two classes of a public middle school in the northern Taiwan. Insruments for data collection includes a two-tier diagnostic test on optics and student worksheets. Five POE activities were designed based on the common alternative conception about optics. Students in the experimental group used worksheets that incorporate scaffolds of scientific explanation during the POE activities. The concrol group students used traditional POE worksheets. The scaffolds of scientific explanation were designed to help students to identify evidences and to emphasize the importance of connections among claim, evidence, and the underpinning scientific priciples. The results showed that: Students used tradional POE worksheets out perform students use worksheets with scaffolds of scientific explaination on scores of the diagnostic instrument. However, no differences were found between the two groups. Finding from analysis of student worksheets were consisted with findings from the diagnostic instrument. Regarding students’ ability of scientific explanation, students who used the scaffolds outperformed than those used tradional POE worksheets on ability to provide appropriate evidences. But their abilities to make claim and provide supports showed no difference between the two groups, possible explanation for outfindings on students’ outcomes of conceptual change and ability of scientific explaination, as well as implicantions for teaching and future research. The scaffolds of scientific explanation in this study not reach significance difference in conceptual change. Possibly caused by POE activities corresponded not precisely enough to the diagnostic instrument. Another reason is the learners’ cognitive overload caused by the scaffolds. The scaffolds help the most in finding evidence of scientific explanation, but the students need more help in describing support to link claim and evidences.