中學生的視覺表徵能力與分子概念理解之探究

Investigating High School Students’ Visual Representational Ability and Molecular Conceptual Comprehension

詹婉約(Wan-Yueh Chan)

指導教授 ： 邱美虹 教授

國立臺灣師範大學/理學院/科學教育研究所/碩士(2010年)

摘要

本研究旨在探討學生對視覺表徵及分子概念的理解、以及視覺表徵及分子概念理解之間的關連。本研究發展視覺表徵能力指標(Visual representational ability index, VRAI)，透過解構的方式瞭解視覺表徵能力，視覺表徵能力指標具有兩大向度，一為視覺表徵能力的四個成分，這些成分為化學中重要的視覺化技能，即知覺、詮釋、轉換和連結、及選擇和評估；二為視覺表徵能力層級，由層級一到層級五。本研究具有兩個測驗工具，一為視覺表徵能力測驗，一為分子概念理解測驗，預試對象為25位九年級學生，信度Cronbach’s Alpha分別為0.88及0.84，正式施測對象為343位國中學生。
研究結果包含視覺化表徵能力、分子概念理解、及視覺表徵能力層級的部分。在視覺化表徵能力方面，第一，由成分一「知覺」的研究結果可知學生對表徵的理解可能與以下因素有關，（一）當表徵中呈現的是單一訊息時，較多重訊息的表徵理解為佳；（二）即便表徵所體現的同為巨觀層級的概念，可在日常經驗中觀察的概念較無法在日常經驗觀察的概念理解為佳；（三）即便只需要對表徵做表面性的描述，微觀表徵對學生而言還是概念負載的；（四）學生傾向於以化學式的表面特徵詮釋表徵。第二，由成分二「詮釋」的研究結果顯示，（一）概念負載有助於學生對表徵的語法規則描述；（二）學生偏向於以表徵所觀察到的表面特徵解釋表徵。第三，由成分三「轉換與連結」的研究結果顯示，大部分學生偏向於以表徵所觀察到的表面特性做表徵間的連結。第四，由成分四「選擇和評估」的研究結果歸納學生對表徵的理解可能有以下趨勢，（一）當表徵所體現的概念具有過程屬性時，較易被學生理解，當表徵所體現的概念牽涉分子本身的認識時，學生較不易理解；（二）學生無法由二維的表徵知覺三維的空間相對位置。
在分子結構概念理解方面，由巨觀層級的研究結果可知，當概念牽涉物質的特性時，則學生的答題表現較那些可直接觀察的概念為低。由微觀層級的研究結果可知，（一）學生傾向於以物質粒子的觀點詮釋原子與分子；（二）學生對化學過程相關概念的理解較原子與分子本身的理解為佳。
在視覺表徵能力層級方面，整合四個成分的整體結果進入「視覺表徵能力指標(VRAI)」後，發現以下幾點，（一）高表現的學生也可能無法在所有解釋表徵的情境下，採取語意層次的解釋；（二）低表現的學生僅能描述巨觀表徵所體現的現象，即便僅需對微觀表徵的外觀進行描述，也無法選擇出正確答案。
本研究針對教學及研究提出幾點建議，就教學建議來說，（一）有關原子與分子觀的概念，即便教科書中包含了各種原子與分子相關的視覺表徵，但可能較不容易被學生理解，在教學上需要被強調；（二）在學習原子與分子之概念時，或許能夠以學生較熟悉的化學過程導入，或者以簡單的過程符號進行原子、分子屬性的解說；（三）教學時宜幫助學生釐清物質粒子觀與原子分子觀的異同；（四）加強學生對微觀表徵的閱讀能力。就研究建議來說，（一）「表徵解構架構修正」中不具有將不同能力學習者分級或歸類的標準，為待確立的表徵架構；（二）閱讀微觀表徵及符號對學習者而言是個複雜的過程，這個過程需要進一步的研究發現。

關鍵字

視覺化 ； 表徵 ； 分子結構

並列摘要

This research examined students’ comprehension of visual representations, conceptions of molecule, and their correlation. In order to deconstruct the visual representational competence, the present study developed a taxonomy of visual representational ability index (VRAI) and an instrument, the components were included in the VRAI framework, that is perception, interpretation, transformation and connection, selection and evaluation. The design of levels of visualization skills were also included in the VRAI. The present study developed two instruments, one is visual representational competence test, and the other is molecule conceptions comprehension test. The internal reliability were .88 and .84 respectively.
The results of visual representational competence revealed that (1) Students comprehended better in representations with single information than in representations with multiple information. (2) Students had difficulties in describing the surface features of representations for the microscopic phenomenon, which were concept-laden to students. (3) Students who held some concepts of molecules could describe the representations based on syntactic rules. (4) Students tended to interpret and connect different representations based on surface features. (5) Students had a lot of difficulties in describing representations which involved the nature of molecule. (6) Students had difficulties in perception of three-dimensional information.
The results of molecule comprehension revealed that (1) Students tended to interpret the concepts of molecule based on the concepts of the nature of particles. (2) Students comprehended the concepts of chemical process than the concepts of the nature of molecule.
The results of visual representational competence revealed that (1) Some of the high performance students could not interpret representations based on semantic meaning. (2) Low performance students could not describe the surface features of microscopic representations.
Several pedagogical implications could be drawn from this study. (1) It appeared that students had limited comprehension in different molecule-related representations, which need to be emphasized in learning. (2) It seems that understanding of process-related concepts may promote students deep understanding of the concepts of molecule. (3) It may be helpful for students to learn how to distinguish the nature of particles and the perspective of molecule.

並列關鍵字

visualization ； representation ； molecular structure

參考文獻

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