The purpose of this study was to investigate the beliefs of six experienced high school science teachers about (1) what is successful science learning; (2) what are the purposes of laboratory in science teaching; and (3) how inquiry is implemented in the classroom. An interpretive multiple case study with an ethnographic orientation was used. The teachers' beliefs about successful science learning were substantively linked to their beliefs about laboratory and inquiry implementation. For example, two teachers who believed that successful science learning was deep conceptual understanding, used verification labs primarily to illustrate these concepts and used inquiry as a type of isolated problem‐solving experience. Another teacher who believed that successful science learning was enculturation into scientific practices used inquiry‐based labs extensively to teach the practices of science. Tension in competing beliefs sets and implications for reform are discussed. ? 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 936‐960, 2004.

ABSTRACT:The purpose of this study was to explore how science teachers' epistemological beliefs and teaching goals are related to their use of lab activities. Research questions include (a) What are the teachers' epistemological beliefs pertaining to lab activities? (b) Why do the science teachers use lab activities? (c) How are the teachers' epistemological beliefs and instructional goals related to teaching actions? Two major aspects of epistemologies guided this study: ontological aspect (certainty/diversity of truth) and relational aspect (relationship between the knower and the known). The ontological aspect addresses whether one views knowledge as one certain truth or as tentative multiple truths. The relational aspect addresses whether one views him/herself as a receiver of prescribed knowledge separating self from knowledge construction or as an active meaning maker connecting self to the knowledge construction processes. More sophisticated epistemological beliefs include the acknowledgement of multiple interpretations of the same phenomena and active role of the knower in knowledge construction. Three experienced secondary science teachers were interviewed and observed throughout an academic course. The findings illustrate that a teacher's naïve epistemological beliefs are clearly reflected in the teacher's teaching practices. However, a teacher's sophisticated epistemological beliefs are not always clearly GOALS AND ACTIONS 141connected to the practice. This seems to be related to the necessary negotiation among their epistemological beliefs, teaching contexts, and instructional goals. Ontological and relational beliefs seem to be connected to different facets of teaching practices. Findings indicate that various syntheses of different aspects of epistemological beliefs and instructional goals are linked to teachers' diverse ways of using lab activities. Implications for research and teacher education are discussed.C

Desert populations of the evergreen dioecious shrub Simmondsia chinensis exhibit sex-related leaf and canopy dimorphisms not present in populations from more mesic coastal environments. Leaves on female shrubs have characteristically larger sizes, greater specific weights, and greater water-holding capacity than male leaves in desert habitats. In coastal scrub environments no significant difference is present, with leaf characteristics of both sexes similar to those of desert male shrubs. Desert female shrub canopies are typically relatively open with little mutual branch shading. In male shrubs canopies are more densely branched with considerable mutual shading of branches. Female plants allocate a greater proportion of their vegetative resources to leaves than do male plants. Considering total biomass, male plants allocate 10-15% of their resources (biomass, calories, glucose-equivalents, nitrogen, phosphorus) to reproductive tissues. Female allocation is dependent on seed set. At 100% seed set females would allocate 30-40% of their resources to reproduction, while female reproductive investment would equal that of males at approximately 30% seed set. Sexual dimorphism and the associated physiological characteristics in Simmondsia act as an alternative to differential habitat selection by male and female plants. Female plants respond to limited water resources in desert areas by increasing their efficiency in allocating limited resources to reproductive structures.

This article presents a theoretical framework in the form of a model on which to base research in scientific literacy and language use. The assumption guiding the framework is that scientific literacy is comprised of the abilities to think metacognitively, to read and write scientific texts, and to apply the elements of a scientific argument. The framework is composed of three theoretical constructs: authenticity, multiple discourses, and Bhabha's Third Space. Some of the implications of the framework are that students need opportunities to (a) use scientific language in everyday situations; (b) negotiate readily among the many discourse genres of science; and (c) collaborate with teachers and peers on the meaning of scientific language. These ideas are illustrated with data excerpts from contemporary research studies. A set of potential research issues for the future is posed at the end of the article.

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