九年級個案學生粒子概念之探討——以擴散作用為例

Case Studies on Investigating the 9th Graders’ Conceptions of Particles : Taking Diffusion as an Example

本研究探討六名九年級個案學生對液體擴散現象中的粒子概念。研究採繪圖與晤談的方式收集學生的粒子概念特質，以及學生有無擁有粒子觀，進而了解學生有無粒子動態行為之概念。研究結果顯示，四名個案學生擁有擴散作用的次微觀概念，三名個案學生能夠使用次微觀概念解釋擴散作用的表現。即使已到了國中三年級，所有個案學生都未具備完全正確的擴散作用知識。因此作者認為教師在教學時除應強調粒子的特性外，且應透過有效的教學與動態評量協助學生建立粒子行為的內在概念表徵（如心智模式），隨時檢測學生的概念狀態。而教材的編排上，亦應著重科學現象中巨、微觀之間的關係並盡早導入粒子概念的課程。

This was a case study to investigate the six 9th grade students’ conceptions of diffusion. Analyses of characteristics of students’ understanding of the particle concepts were generated from their drawings and interviews. The results showed that some case students had submicroscopic concept of diffusion and they could use the concept to explain the phenomenon of diffusion. However, all the case students did not have the complete understanding of diffusion. It is our recommendation that not only do teachers have to emphasize on the characteristics of particles during instruction, but also have to help students build internal appropriate representations (e.g., mental models) of particles at the submicroscopic level. We also argue that teachers can monitor students’ conceptual status via alternative assessment methods, such as interview and drawing. The relationships of macroand microscopic views of particles should also be introduced earlier in the textbooks.