本研究依據氣體動力論模型發展二階層(two tiers)試題做為診斷性工具,探究國、高中學生在不同年級對有關氣體的各種概念所抱持的迷思概念(misconception),並對其產生的迷思概念嘗試以不同角度採取適當的類型加以分類,並試圖找尋其概念背後的心智模式及概念形成的成因。 此氣體概念二階層試題診斷工具的編製流程,首先以開放式紙筆問卷引出對台北市國、高中各兩個班學生對氣體概念的各種想法,並在學生答案分析後做適當類型的歸類,然後在各類型迷思概念的學生,實施半結構性晤談,以了解學生真正的想法來修正研究者歸類的最初假設,及補充開放式紙筆問卷所未發現的盲點。不斷重複上述步驟將試題做更深入的修正分析及最後由學科專家審查確認,以發展一份具有信效度的氣體迷思概念二階層試題。 本研究的研究對象為台北市立某高中一、二年級學生共302人及台北市立某國中一、二、三年級共368人。 以氣體迷思概念二階層試題實測結果發現:1學生對氣體粒子本質的瞭解隨年級成正相關。 2大部分的學生對於「氣體壓力是由於氣體粒子碰撞模式所產生的」並不了解,認為氣體壓力是氣體活性大小、分子量大小、擠壓程度等不同模式所產生。 3學生對於兩不同氣體擴散時運動速率,認為壓力相同時運動速率就會相同,並不了解分子量大小不同時速率快慢不同的關係。 4 學生認為氣體的活性就是氣體的運動快慢程度,並非化學上所定義的氧化力的大小,隨年級升高此迷思降低。本研究結果所呈現的學生迷思概念類型及其比例可做為教師教學時的參考資料庫。
This research is based on “Microscopic Gas Model” to develop a two-tier test that intend to diagnose different types of misconceptions of gas among secondary school students at different grades and figure out students’ mental model behind each type of misconception. The respondents of this research are 302 tenth and eleventh grade school students and 368 seventh, eighth, and ninth grade students who study in the same junior high school in Taipei. The major findings of this study are summarized as follows:1. The students’ understanding about gas properties is positively correlated with students’ grades. 2. The students’ perceptions of gas pressure are misled. Most students thought that gases exert pressure through different gas volatilities, molecular weight, and the degree of push. However, gases exert pressure because their particles constantly move around and collide with the walls of the container holding the gas. 3. In terms of motions of two types of gases, the students perceive that the gases’ velocities are equal under the same pressure, but they have not got the idea that velocities are also affected by molecular weight. 4. The students thought that gas volatility represents its speed of motion, but in fact, gas volatility represents its tendency of oxidation. This misconception becomes less serious as the students with higher grades. 5. As the grade gets higher, it is not necessary to develop better conceptions with the dynamic nature. This research provides an empirical foundation for next step large-scale study, which could result in better understandings of the types of misconceptions and the spread of each type held by different levels of ages. Teachers might furthermore take research results as reference to clarify students’ misconceptions revealed by the study.