Inquiry the eleventh students』 mental models and paths of conceptual change in learning the nature of ideal gas particles via multiple modeling activities

• Main Authors: Shiao-Lan Chung, 鍾曉蘭
• Other Authors: Mei-Hung Chiu
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/43868132647239476754

碩士 === 國立臺灣師範大學 === 科學教育研究所在職進修碩士班 === 95 === In the process of learning chemistry, the microscopic concept of particles has been regarded as an important basis in understanding certain chemistry concepts, such as states of matter, ideal gas particles models, collision theory, or chemical equilibrium. It is difficult for students to be aware of and experience the ideas about the micro world in chemistry in their daily lives. They even make plenty of incorrect inferences concerning the macroscopic phenomena of gas, which in turn lead to numerous misconceptions (Novick & Nussbaum, 1981; Millar, 1990; Benson et al., 1993). To find out students』 difficulties in learning related concepts of ideal gas theory, based on the misconceptions / mental models of gas particles discussed in the literature, this research designs a series of diagnostic paper-and-pencil tests (There are 82 12th students in high school participate pre-test, forty-five students are male and thirty-seven students are female. The reliability is 0.913) about gas volume, gas pressure, vapor pressure, diffusion, and gas particles movements in the micro world. The purpose of this research attempts to explore students』 various types of mental models of ideal gas. In practical teaching, the researcher, based on the properties (rigid particles; random motions) of ideal gas particles models, designs multiple representations modeling activities. Through analyzing the distribution and the evolutionary pathways of mental models and comparing the variation of 3C (Correctness, Consistency, Completeness) before and after teaching as well as the follow-up tests (Chi & Roscoe, 2002; Vosniadou, 2002; Chiu, 2006), this research would like to see if multiple representations modeling activities (the experimental group: 39, male: 27, female: 12) improve students』 conceptual change in scientific learning toward ideal gas than the traditional way of textbook teaching (the control group: 40, male: 32, female: 8) more effectively. After two weeks』 (totally eight class periods) teaching, the researcher analyzes the correctness, consistency and completeness of students』 conceptions on gases between the two groups, and their responses in the five units of dynamic assessments. 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 (paired-t test, correctness: t=.781, p=.440; consistency: t=1.705, p=.081; completeness: t=1.04, p=.306). However, it shows significant difference between two groups after teaching (ANCOVA, correctness: F=36.4, p=.000; consistency: F=40.9, p=.000; completeness: F=42.4，p=.000). Especially in the micro phase, the correctness of the experimental group is significantly superior to that of the control group (F=43.6, p=.000). It indicates that the multiple representations modeling teaching may assist students to develop correct microscopic models of gas particles motion. (2) In the process of dynamic assessments, the scores in the four assessments of the experimental group are far better than those of the control group except in the second assessment. (3) Students』 mental models are judged from their explanations on six questions related to micro conceptions on gas pressure in the diagnostic test. Therefore, the students』 mental models are categorized into ten types: scientific model, scientific flaw, scientific models plus others, molecular weight model, volume model, attraction model, kinetic energy model, active model, bi-mental model, and inconsistent mixture model. The evolution of the mental models towards gas pressure in the experimental group goes as follows: mixture (30.1%) → scientific flaw (35.8%) → scientific flaw (46.1%).The evolution of the mental models towards gas pressure in the control group goes as follows: mixture (45.0%) → mixture (45.0%) → mixture (37.5%). The mental models of the students in the experimental group move towards scientific model / scientific flaw. Due to the lack of consistent multiple representations of particles with phenomena in control group, it is difficulty to help the students in control group develop correct mental models. (4) Multiple representations modeling teaching and dynamic assessments help students build up the ontology of emergent process. Through the multiple representations modeling teaching, such as visual mixture, concrete mixture, math mixture, and motion mixture, the students in the experimental group develop a full concept on rigid particles. Moreover, they recognize the random motion of particles in the micro world and understand that the factors contributing to gas pressure come from the transition of kinetic energy in each volume unit when fast-moving particles crash the wall of the containers. Therefore, there are 48.7% of the students in the experimental group undergo some of the more difficult conceptual changes, such as from matter to process or from direct process to emergent process shortly after teaching. And 20.5% of the students in the experimental group gradually form the emergent process ontology in their learning process. (5) From the students』 open-ended questionnaire, we realize most students, in terms of their emotions, are positive towards multiple representations modeling activities. This research attempts to apply multiple representations modeling activities to ideal gas teaching. And it shows the teaching results excel those of the traditional textbook teaching. The findings of this research encourage science teachers to adapt modeling teaching in their classroom activities. With the time allowance, science teachers should help students observe and understand the scientific models embedded in phenomena through the interactions between expressed models and different representations, which thus repair or modify their mental models.