Students' conceptions of solubility : a teacher-researcher collaborative study

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 ofCurriculum and Pedagogy (EDCP), Department ofGraduat