Authors Index, Volume 23 (2001)

Authors Index

Authors Index, Volume 23 (2001)     

Characteristics of 5th Graders' Logical Development Through Learning Division with Decimals

When we consider the gap between mathematics at elementary and secondary levels, and given the logical nature of mathematics at the latter level, it can be seen as important that the aspects of children's logical development in the upper grades in elementary school be clarified. In this study we focus on the teaching and learning of “division with decimals” in a 5th grade classroom, because it is well known to be difficult for children to understand the meaning of division with decimals, caused by certain conceptions which children have implicitly or explicitly. In this paper we discuss how children develop their logical reasoning beyond such difficulties/misconceptions in the process of making sense of division with decimals in the classroom setting. We then suggest that children's explanations based on two kinds of reversibility (inversion and reciprocity) are effective in overcoming the difficulties/misconceptions related to division with decimals, and that they enable children to conceive multiplication and division as a system of operations.     

Talking About Teaching Episodes

This paper examines two types of discourse in which teachers engage when discussing case studies based on classroom episodes, and the ways in which the availability of video data of these episodes may motivate a shift in the mode of discourse used. We interviewed two pairs of secondary school mathematics teachers after they had read a case study based on a 16-minute mathematics classroom episode taped in a secondary school in the United States. During each interview, a multimedia version of the case study, including video of the original episode, was available to the participants. We identify two modes of discourse engaged in by the teachers during the interviews: Grounded Narrative and Evaluative Discourse. We examine and identify the characteristics of the two discourse forms, drawn from both video and textual analysis. These characteristics are self-reflective talk, perspective, ethics, and linguistic patterns. The identification of two modes of discourse is relevant for researchers and teacher educators using case studies or video recordings. In addition, the findings provide insight into how teachers are “seeing” classroom events in a video case study.     

Sensitivity analyses of cables to suspen-dome structural system

The construction of the cables is a key step for erecting suspen-dome structures. In practical engineering, it is difficult to ensure that the designed pre-stresses of cables have been exactly introduced into the structures in the site; so it is necessary to evaluate the influence of the variation of the pre-stresses on the structural behavior. In the present work, an orthogonal design method was employed to investigate the pre-stressed cables'sensitivity to the suspen-dome system. The investigation was concentrated on a Kiewitt suspen-dome. Parametric studies were carried out to study the sensitivity of the structure's static behavior, dynamic behavior, and buckling loads when the pre-stresses in the cables varied. The investigation indicated that suspen-dome structures are sensitive to the pre-stresses in all cables; and that the sensitivity depended on the location of the cables and the kind of structural behavior. Useful suggestions are given at the end of the paper.     

Clusters,Innovation and Tertiary Education

The purpose of this paper is to investigate the integration between research findings produced at the University and Community College levels and local SMEs (small and medium enterprises) as it impacts regional innovation systems and in particular the prospect of cluster formation. The paper explores certain factors that have been identified in international literature as being critical to fostering innovation in non-metropolitan regions. These factors include government policies and programmes, internal and external infrastructure, partnership or research links among educational institutions, and support from local business and civic leaders. Stakeholders from non-metropolitan regions were asked to judge the level of effectiveness with reference to these development “factors” while highlighting weaknesses, strengths, and effects on innovation in their locale.     

Solid-phase microextraction for flavor analysis in Harari Khat (<Emphasis Type="Italic">Catha edulis</Emphasis>) stimulant

This research examined the typical flavor compounds in the commonest type of Khat called Harari Khat grown in the region of Ethiopia. Twenty-eight compounds, which includes 1,2-Propanedione, 1-Phenyl, Hexanol, Hexanal compounds, Limonene, Benzaldehyde with other flavors, were extracted by polydimethylsiloxane at room temperature for 30 min from Khat samples, and identified by solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). This method needs no organic solvents and required minimal sample. Project supported by scholarship from China     

Stable individual differences on developmental tasks in young yellow-crowned parakeets,<Emphasis Type="Italic">Cyanoramphus auriceps</Emphasis>

We report on stable individual differences in young yellow-crowned parakeets across 38 tasks of cognitive development on three scales involving object permanence, means-end relations, and spatial relations. Stable performance ranks on blocks of tasks emerged after 13 weeks in two groups of sibling parakeets, one hand-reared and the other parent-reared. Examination of subject characteristics, such as hatch order, sex, general activity level, avoidances, latencies, social status, and errors, showed no significant correlations with these performance ranks. Characteristic individual approaches to unstructured play activities (from a fourth scale) were consistent with individual behavioral differences seen on the structured cognitive tasks.     

Neighborhood disadvantage: pathways of effects for young children

The present study used Canadian National Longitudinal data to examine a model of the mechanisms through which the effects of neighborhood socioeconomic conditions impact young children's verbal and behavioral outcomes (N= 3,528; M age = 5.05 years, SD= 0.86). Integrating elements of social disorganization theory and family stress models, and results from structural equation models suggest that both neighborhood and family mechanisms played an important role in the transmission of neighborhood socioeconomic effects. Neighborhood disadvantage manifested its effect via lower neighborhood cohesion, which was associated with maternal depression and family dysfunction. These processes were, in turn, related to less consistent, less stimulating, and more punitive parenting behaviors, and ultimately, poorer child outcomes.     

综合理科课程理解的几个误区

通过详实的资料 ,对综合理科课程的涵义、产生和发展、课程类型、教学目标、教学评价特征以及与分科理科课程和理科综合考试的关系进行了全面论证 ,从而澄清了当前对于综合理科认识的几个误区     

Enhancing Elementary Science Teachers’ Knowledge of Teaching: The Case of Designing and Implementing an Instructional Unit

This article provides a model for the professional development of elementary science teachers. The model focused on integrating different domains of knowledge into science teaching, including the knowledge of the science curriculum, especially scientific inquiry, teachers knowledge, and students knowledge. The two case studies in this article revealed that the teachers construct their knowledge in a social context. The constant reflections on the experiences helped them to generate alternative teaching approaches. The findings suggest that the model of the project had two functions. First, it provides a useful strategy to help science teachers to bridge the gap between theories of teaching and their own teaching practices. Second, it provides a social learning environment for learning how to teach science.