探討動態類比對於化學平衡概念學習之研究 -八年級學生概念本體及心智模式之變化-

Abstract

動態平衡是許多自然學科的基礎，但是，由於巨觀與微觀世界的差異，造成學習上的困難（van Driel, 2002）。而以Chi等人的觀點而言，動態平衡的困難點在於其本體屬性為突現本體，而非直接過程本體。於是許多研究開始設計各種教學策略，以幫助學生進行學習，而最常被提及的兩種教學方式，分別為類比（e.g. Johnstone, MacDonald,& Webb, 1977; Olney, 1988）與電腦動畫（e.g. Hameed , Hackling, & Garnett, 1993）。本研究結合這兩種方式發展出「動態類比」，以動畫的方式展現類比物與目標物的對應，冀望能夠為學生的學習帶來更多的助益。 依據上述的目的，本研究主要的研究問題為：一、經由類比及動態類比的教學方式，是否可以幫助學生於動態平衡單元的學習？二、經過教學之後，心智模式與概念本體的改變情形為何？三、心智模式、概念本體、學習態度對於概念學習的可能影響情形？因而本研究選擇溶解平衡、化學平衡、相平衡三個教學主題，選取三個八年級的班級，並隨機分派至對照組、類比組、以及動態類比組，以進行教學研究，並由每班中選出六位標目學生，進行晤談以瞭解學生心智模式的變動情形。 本研研究的結果如下： 1. 就概念整體的表現而言，動態類比組的表現是優於類比組的，而類比組的表現優於對照組。 2. 就概念本體得分而言，動態類比組與類比組於本體屬性的得分皆優於對照組，然而動態類比組與類比組有著相近的表現，兩組中產生概念跨越的學生其維持的情形也較佳。 3. 就心智模式而言，學生於動態平衡單元中的四種主要心智模式分別為：雙向心智模式、單向-雙向心智模式、單向心智模式、靜止模式。動態類比組後測晤談中，83%的學生其主要心智模式為雙向心智模式，而類比組為66%，對照組為50%。且關於心智模式的融貫性與一致性皆是動態類比組優於類比組，類比組優於類比組的情形。 4. 就情意面向而言，動態類比組認為此次教學可以幫助理解、較為有趣、而且並未造成學習上的負擔，對於本次教學所持的態度是最為正向的，而類比組次之，對照組則趨向於中性的看法。 5. 學生若具備較科學心智模式（R平方為0.67）、對於粒子運動的本體屬性有較好的認識（R平方為0.25）、對於本次的教學如果抱持較正向的態度（R平方0.09），那麼也就會有較佳的概念學習。研究中的發現是心智模式對於概念學習的影響最大，而本體概念次之，而情意面向的影響層面較小。

綜上所述，由於本研究之「類比物」──「舞者」與「目標物」──「粒子」的對應，因而在概念本體上的表現，類比組與動態類比組兩組的成效相近；而就概念完整性而言，則動態類比組較優，因此動畫似乎可以幫助建立較佳的心智模式。動態平衡概念雖難，但是，只要選擇適當的教學方式，例如：本研究的類比「舞會」或是動態類比的方式，還是可以增進學生的學習。

The concept of dynamic equilibrium has played an important role in learning chemistry. Because of the difference between macroscopic and microscopic view of phenomenon, students have difficulties to learn concepts related to equilibrium (van Driel, 2002). According to Chi’s point of view, difficulty of learning concepts of dynamic equilibrium lies in its ontological attribute which belongs to ‘emergent casual processes’, not ‘direct casual processes’. Therefore, many researchers have been engaged in designing meaningful teaching strategies helping students overcome this difficulty. Analogy (e.g. Johnstone, MacDonald,& Webb, 1977; Olney, 1988) and computer animation (e.g. Hameed, Hackling, Garnett, 1993) have been mentioned most often. This research integrated these two teaching approaches to develop Dynamic-analogy instruction, which intended to map between target domain and source domain in the filed of equilibrium. The purpose of this study was to examine how students could benefit from the instruction designed via simulation and analogies. According to the purpose mentioned above, the main research questions were as follows. First, could analogy and dynamic-analogy help students learn dynamic equilibrium or not? Second, how students’ mental models and conceptual ontology would be changed after instruction? Third, what are the possible relations between students’ mental models, conceptual ontology, attitudes toward learning, and concept learning? Thus, this research chose three sub-topics among dynamic equilibrium: solution equilibrium, chemical equilibrium, and phase equilibrium to fulfill the purposes. There were three 8th-grade classes randomly assigned to three groups: the comparison group, the analogy group, and the dynamic-analogy group. Six target students were interviewed from each group. The major results of the research were as follows: 1. As for concept learning, both dynamic-analogy group and analogy group performed better than the comparison group. In addition, the dynamic-analogy group had the a little higher achievement than the analogy group. 2. As for the conceptual ontology, the dynamic-analogy group and the analogy group had similar scores that revealed a better performance than the comparison group. There were more students changed from ‘direct causal process’ to ‘ emergent causal process’ in these two groups, and the retaintion of the concepts was also better. 3. The researcher identified four mental models of dynamic equilibrium from the students’ performance. They are: first, bidirectional model; second, unidirectional model; third, unidirectional model; fourth, static model. In the dynamic-analogy group, 83% target students’ major mental models were ‘bidirectional model’ which is the scientific model, 66% for the analogy group and 50% for the comparison group . Moreover, the dynamic-analogy group had the most consistent and coherent mental model. 4. About learning attitude, students in dynamic-analogy group thought that this teaching was interesting, not too hard to understand, and might promote the understanding. Dynamic-analogy group had the most positive attitude. 5. Students, who had better scientific mental model(R square is 0.67), had more correct conceptual ontology attributes (R square is 0.25), had more positive attitude toward learning (R square is 0.09), would have higher scores in post test and learn better. The finding in this research was that mental model had the greatest influence in conceptual learning.

In summary, the analogy group and dynamic-analogy group got higher scores in concept ontology test, in a result from mapping between source domain--dancers and target domain--particles. In addition, dynamic-analogy group’s was more integrity. Therefore, dynamic representation may have high potential for helping students to develop more coherent and consistent mental models. However, the result revealed the difficulty of learning dynamical equilibrium still existed. Students could learn well as long as teachers could choose a suitable instruction to promote students’ learning, for instance, the analogy -- dancing party or dynamic-analogy.