The purpose of this study was to correlate the Vegetation of the Woodbine Sands with the edaphic factors. In the laboratory an analysis of the edephic factors was made of the twenty-two soil types collected from the three formations. The results of these and other analysis are shown in tables and graphs. The results indicate that the vegetational cover of an area that is uniform in its origin and in its resident soil factors is determined by the edaphic factors present.

This study describes first and second year university physics students' understanding and reasoning of the concepts, angular speed and angular acceleration. The analysis was based on student responses to various tasks presented to them during one hour long interviews. These responses were characterized from a phenomeno graphic research perspective developed by Marton (1981) and his colleagues at Gothenburg University in Sweden. The findings of the study are described by categories of description and by categories of reasoning. Categories of description characterize; students' conceptualizations of angular speed from different frames of reference, and the ways in which students make comparisons of the angular speeds of two objects. Categories of reasoning characterize the ways in which students were thought to reason about the concepts of angular speed and angular acceleration in several task settings. Interpretation of these findings are discussed with reference to the role a typical introductory physics textbook may have had in shaping the way in which students think about these angular kinematic concepts. Finally, instructional implications and directions for future research are given.

This study describes first and second year university physics students' understanding and reasoning of the concepts, angular speed and angular acceleration. The analysis was based on student responses to various tasks presented to them during one hour long interviews. These responses were characterized from a phenomeno graphic research perspective developed by Marton (1981) and his colleagues at Gothenburg University in Sweden. The findings of the study are described by categories of description and by categories of reasoning. Categories of description characterize; students' conceptualizations of angular speed from different frames of reference, and the ways in which students make comparisons of the angular speeds of two objects. Categories of reasoning characterize the ways in which students were thought to reason about the concepts of angular speed and angular acceleration in several task settings. Interpretation of these findings are discussed with reference to the role a typical introductory physics textbook may have had in shaping the way in which students think about these angular kinematic concepts. Finally, instructional implications and directions for future research are given. / Education, Faculty of / Curriculum and Pedagogy (EDCP), Department of / Graduate

Learning difficulties resulting from students holding conceptions of scientific concepts which are at variance with those presented in curricular materials have been identified in the literature in a number of areas of science. In this study a number of student learning difficulties related to the concepts of growth and the cell were identified. More specifically, this study was designed to investigate whether alternative conceptions held by students prior to instruction were, in part, responsible for these learning difficulties. The study also investigated whether omissions in instruction contributed to these learning difficulties. Finally, the study examined changes in student conceptions after formal instruction. Through concept analyses of growth and the cell, two semi-structured interview protocols were developed. The Growth Protocol was used to interview students in Grades 3, 5, and 7 and the Cell Protocol was used to interview students in Grade 10. The students in Grades 3 and 10 were interviewed both before and after instruction. The conceptions of the students identified in the transcripts were classified into a number of categories specific to the constituent concepts of growth and the cell. Students at all grade levels were found to hold a wide variety of alternative conceptions regarding the concepts in question. The majority of these alternative conceptions were identified in more than one student and did not reflect current scientific or curricular understandings of growth or the cell. Rather, it seemed that these alternative conceptions reflected student attempts to make sense of concrete experiences with phenomena in their surroundings. After instruction at both the elementary and secondary level, the majority of students did not incorporate most of the scientific concepts as they were presented during instruction. The older students did not hold a conception of cell differentiation nor did the majority of students link the microscopic phenomena of cell division with the macroscopic phenomena of growth in organisms other than humans. The variability of alternative conceptions of mitosis and meiosis after instruction strongly suggested that the students experienced learning difficulties with respect to these concepts. The results of this study imply that in order to effectively move the learner from alternative conceptions to scientific conceptions both curricular and instructional strategies must shift their emphasis from one of presenting only disciplinary knowledge to one of considering also the prior knowledge that the learner brings to the instructional setting. / Education, Faculty of / Curriculum and Pedagogy (EDCP), Department of / Graduate

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