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No description available.

No description available.

published_or_final_version / Education / Master / Master of Education

The purpose of this study was to assess the extent of discovery learning opportunities in Arizona secondary chemistry classrooms and to determine their relationship to performance in selected areas of freshman college chemistry at the University of Arizona. For the purpose of this study two questionnaires were developed, one to gather data relating to students' participation in discovery learning activities in high school chemistry and the other to assess their use of learning resources at the University of Arizona. Interviews were conducted with 15 volunteers from the subjects of this study. The information provided by these volunteers concerning their high school chemistry background was consistent with information obtained from the questionnaires. Examination and laboratory scores were obtained from the records of the chemistry department, to assess student performance in lecture and laboratory. The students' responses on the Learning Activities Questionnaire were used to form a discovery index score, which was correlated with college chemistry examination scores, college laboratory scores, and student-reported use of learning resources. The lack of relationship between the discovery index scores and college chemistry examination scores was indicated by a partial correlation of -.10 which was not statistically significant at the .05 level. A statistically significant partial correlation of .20 indicated the discovery index scores were related to college laboratory scores. No significant relationship was found between discovery index scores and students' use of learning resources at the University as indicated by the Pearson correlation of .15, which was not significant at the .05 level.

For the last fifteen years, research on students' conceptions of physical phenomena has been directing our attention to the value of knowing and considering children's prior ideas in science teaching. Although many who are concerned with science education are aware of and see wisdom in this perspective of teaching, there are many realities, including the content of the discipline, that pose great challenges in translating it into practice in science classes. Currently, in collaboration with teachers, science educators are actively conducting classroom studies. In this process, teachers as researchers are making reflective inquiries into their own students' learning. This study followed a similar framework of research at a microcosmic level. It entailed elicitation of thirteen Grade 11 students' individual prior conceptions of solubility and a teacher-researcher collaboration to incorporate these conceptions in the instruction of a unit on solution chemistry. Consequently, the study presents a phenomenography of solubility, narrates a story about classroom instruction which took students' conceptions into consideration, reports four case studies on students' conceptual growth and changes, and outlines some of the factors that facilitate or constrain collaborative teaching that focuses on student understanding of subject matter. The students' prior conceptions of solubility were categorized into six categories of description: 1. physical transformation from solid to liquid 2. chemical transformation of solute 3. density of solute 4. amount of space available in solution 5. properties of solute 6. size of solute particles With regard to learning chemistry, these conceptualizations made clear four issues: (1) students' explanations were bounded by their perceptions, (2) students extended macroscopic explanations to a microscopic level, (3) students made inappropriate links to previous chemistry learning, and (4) students used the language of chemistry non-discriminately. After studying a unit on solution chemistry, two more categories of description were added to the pre-instructional categories: 1. chemical structure of components 2. solution equilibrium After instruction, the students attributing to the initial six categories of description' diminished in number. The newly acquired conceptions of solubility reflected insufficient explanatory power and were merely overlaid with the chemical language. Learning the language of solution chemistry and acquiring some theoretical understanding of it were reflected in the change between pre- and post-instructional conceptions. This conceptual change can be considered as evolutionary. It was inferred that the abstract and ambiguous nature of chemical theories and principles sets limits to conceptual change teaching. The influences that facilitated the collaborative efforts include: (1) the teacher's attempts to incorporate students' conceptions, (2) the teacher's openness and willingness to assess her own methods of teaching chemistry, (3) the teacher's reflections about the researcher's constructivist teaching, and (4) the researcher's active participation in the classroom interactions. The four most important influences that seriously constrained the collaborative efforts to link students' conceptions with formal chemistry were: (1) the lack of time to devote to the topic of solution chemistry, (2) the lack of teacher time to plan lessons together in order to incorporate students' conceptions, (3) the lack of practical experience on the part of both the researcher and the teacher in developing specific teaching strategies which acknowledged students' prior belief in this content area, and (4) the lack of time to develop common perspectives and a shared language. This study has implications for both teachers and researchers. Specifically, it implies that students' conceptions form an integral component of chemistry instruction—as points of origin for lesson planning and development of curricular materials It also implies that through science educators' modelling and practising in their "teaching and learning" courses, pre- and in-service teachers be challenged to seek answers for epistemological questions such as: What is chemical knowledge? and, How is it acquired? A general implication is that both teachers and researchers, rather than being fence-makers, must strive to be bridge-builders so that they can be learners of each other's theoretical and practical experiences. / Education, Faculty of / Curriculum and Pedagogy (EDCP), Department of / Graduate

published_or_final_version / abstract / Education / Master / Master of Philosophy

Dealing with the college laboratory program in general chemistry, this study compares the effects of exercises based on current national problems with the effects of traditional laboratory exercises. The study has been prompted by the recent emphasis on topics of national interest in the undergraduate chemistry curriculum. These topics include air and water pollution, drug addiction and analysis, tetraethyl-lead additives, insecticides in the environment, and recycling of wastes. The relevant experiments are taken from recent issues of the Journal of Chemical Education. The traditional exercises, from the laboratory manual Chemistry in the Laboratory, by Watt, Hatch, and Lagowski (New York, Norton, 1964), deal with such topics as chemical composition, gas laws, solutions, and acids and bases.

A research report submitted to the Faculty of Science, in partial fulfilment of the requirements for the degree of Master of Science, University of the Witwatersrand, Johannesburg, 2015. / Pedagogical Content Knowledge (PCK) is a knowledge base for teaching that has been shown to be topic-specific. PCK in a particular science topic enables a teacher to pedagogically transform Content Knowledge (CK) to teach that topic. This ability to transform CK for teaching purposes is a version of PCK recognised as Topic-Specific Pedagogical Content Knowledge (TSPCK). TSPCK, like PCK, is not transferable, thus we cannot assume that good pedagogical transformations observed in one topic can be consequently observed in another. In addition it has been shown that the PCK knowledge base for teaching is tacit in nature. This means that most teachers with such a knowledge base are not aware of it explicitly, or how they develop it. The purpose of the study was to explore the mechanism which pre-service teachers used to apply learnt reasoning to transform CK in a new topic.

The development of student’s mental models of chemical substances and processes at the molecular level was studied in a three-phase project. Animations produced in the VisChem project were used as an integral part of the chemistry instruction to help students develop their mental models. Phase one of the project involved examining the effectiveness of using animations to help first-year university chemistry students develop useful mental models of chemical phenomena. Phase two explored factors affecting the development of student’s mental models, analysing results in terms of a proposed model of the perceptual processes involved in interpreting an animation. Phase three involved four case studies that served to confirm and elaborate on the effects of prior knowledge and disembedding ability on student’s mental model development, and support the influence of study style on learning outcomes. Recommendations for use of the VisChem animations, based on the above findings, include: considering the prior knowledge of students; focusing attention on relevant features; encouraging a deep approach to learning; using animation to teach visual concepts; presenting ideas visually, verbally and conceptually; establishing ‘animation literacy’; minimising cognitive load; using animation as feedback; using student drawings; repeating animations; and discussing ‘scientific modelling’. / Doctor of Philosophy (PhD)