探究八年級學生對電化學的概念改變歷程

Abstract

本研究根據文獻所提及電化學的迷思概類型，設計出一系列有關「離子移動」、「通路概念」、「物質增減」、「粒子行為」及「鹽橋概念」的診斷式紙筆測驗（題型包含二階層測驗試題、單一選擇題、填充及作圖題），預試對象為國三學生，男：87，女：101，共計188人，信度為0.936，診斷式紙筆測驗用來探討學生電化學的迷思概念。

為調查所發展的多重表徵教學可以協助學生電化學概念的學習成效，以宜蘭縣某國中之57名八年級學生為研究樣本，依準實驗研究設計分為實驗組（28人，男：15、女：13）與對照組（29人，男：18、女：11）。學生在「電化學」學習上的教學策略，包括文本教學，動手作實驗，電腦動畫，微型化學及角色扮演。教學活動均是為了使學生發生概念改變，並比較該教學對學生之影響，並對實驗組學生施以問卷調查，瞭解學生對此種教學的看法。再者，本研究亦想探討老師的教學策略對學生的學習成效。

經過共計九堂課的教學後，分析兩組學生教學前、後的總分、電化學分項概念、概念的屬性及層次，以及三次動態評量的答題情形，在量化上，以spss分析概念的表現，研究結果分述如下： （1）在教學成效方面：實驗組與控制組兩組學生在教學前並未達顯著差異（t=0.26，p=0.793），教學後則達到顯著差異（ANCOVA，後測：F=8.29， p=0.006；延宕後測：F=6.18，p=.016）。 （2）在分項概念的組間比較（ANCOVA）中，實驗組與控制組兩組學生在分項概念未達顯著差異，後測在「通路概念」、「鹽橋概念」的概念上達顯著差異。延宕後測於「離子移動」、「通路概念」、「物質增減」及「鹽橋概念」均達顯著差異。 （3）在教學過程的動態評量中，實驗組的得分皆顯著優於控制組，兩組學生除了第一次評量（電離說: t=-1.79，p=0.080）未達顯著差異，在其他的動態評量上均達顯著差異（鋅銅電池: t=-3.79，p=0.000，電解水: t=-2.27，p=0.030）。

由結果發現，實驗組的學生的學習成就顯著高於對照組，顯示本研究所開發之多重表徵教學法能有效地促進學生概念的學習與學習興趣。另外，問卷結果顯示，學生對本教學模型於學習的幫助給予正面的肯定，也喜歡此種的上課方式。 而在教學策略方面，學生對於研究教師給予正面的評價，因此在學校的教學中，實施多重表徵的策略，將更有意義地促進學生的學習。

To find out students’ difficulties in learning concepts of electrochemistry, the researcher designs a series of diagnostic paper-and-pencil tests（including two-tier test 、multiple choice questions and blank-filling and making graphs） about the movement of ions , the concept of a circuit, gain or loss of the substance, the behavior of the particles, and salt bridge. There are 188 ninth grade students（87 boys and 101 girls.）in junior high school participate pre-test. The reliability of the instrument is 0.936. The purpose of this research attempts to explore students’ misconceptions about electrochemistry.

In order to investigate the impact of multiple representations teaching of students’ learning in study. This research took quasi-experimental design, and the samples consisted of 57 eight grade students in I-Lan county, who divided into two classes. One class was experimental group（28 in total, 15 males and 13females） and the other was control group（29 in total, 18 males and 11 females）. The strategies of teaching electrochemistry in this research included text-teaching, experiment, computer-aided animation media, microscale chemical experiment and role-playing. All kinds of instructional methods were given respectively in order to make conceptual change happen. Comparison among both groups has been made to determine the effect of the teaching methods, and a questionnaire has been conducted along with the students from the experimental group to understand their opinions on this multiple representation approach. Furthermore, this experiment also wishes to investigate the effects on students’ achievement in learning due to instructors’ teaching strategies.

After nine-class-period teaching, the researcher analyzes the total score of students conceptions, the subconceptions on electrochemical concepts between the two groups, and their responses in the three units of dynamic assessments.About quantitative analysis,the analysis on conception performance is operated with SPSS software. The outcome of the research can be summarized as follows:

（1）The effectiveness of teaching: There is no significant difference between the control group and the experimental group before teaching (t=0.26，p=0.793). However, it shows significant difference between two groups after teaching （ANCOVA, posttest: F=8.29, p=0.006; delayed test: F=6.18, p=0.016）. （2）In the subconceptions of electrochemistry There is no significant difference of subconceptions of electrochemistry between the control group and the experimental group before teaching. However, it shows significant difference between two groups after teaching in posttest（the concept of a circuit and salt bridge」）and in delayed test（the movement of ions, the concept of a circuit, gain or loss of the substance and salt bridge）. （3）Dynamic assessments: In the process of dynamic assessments, the scores in the three assessments of the experimental group are far better than those of the control group.It shows significant difference between two groups after teaching（electrochemical cell: t=-3.79，p=0.000，the electrolysis of water: t=-2.27，p=0.030） except in the first assessment（the theory of electrolytic dissociation: t=-1.79，p=0.080）.

The key finding from this study, the experimental group achieved a higher score compared to the control group. It revealed that the multiple representations teaching developed by this research can promote a better concept developing and a greater learning desire more efficiently. Furthermore, as for theresult of the questionnaire, the students gave positive feedbacks towards the teaching models for its contribution in learning. From the aspect of teaching strategy, the students had positive comments toward this research; therefore, it is possible to implement multiple representation approach in school teaching to promote students' learing meaningfully.