试论数学问题教学中常用的数学思维方式

数学思维是学习数学知识过程中难得的、实用的方法,它同时又是教师在讲授教学理论过程中应当注意加以提炼并引导学生持续掌握、运用进而解决实际问题的一种能力。本文试图通过一些数学问题的分析解答,凸显数学思维及其作用,以达到引起读者关注并试图体验之目的。     

The Effect of Cooperative and Mastery Learning Methods on Primary Grade Students' Learning and Retention of Economic Concepts

Empirical studies have shown the positive effects of combining cooperative and mastery learning methods on mathematics achievement higher order questioning skills, and originality, but little is known, at present, about the effects of cooperative-mastery learning in other subject areas or on other cognitive outcomes. The problem of this study was to explore the effects of cooperative and mastery learning methods, alone and in combination, on first and second grade students' learning and retention of basic economic concepts. A 2 X 2 (cooperative X mastery) factorial design compared the achievement of one hundred-twenty students who were individually randomly assigned (using grade level as a stratification variable) to one of four treatment conditions—instruction on basic economic concepts using (1) cooperative learning, (2) mastery learning, (3) cooperative-mastery learning, or (4) a control treatment (no cooperative or mastery learning). All subjects were administered a written pretest, post-test, and delayed post-test on their understanding of economic concepts. To further probe children's understanding of economic concepts, a randomly selected sub-sample of sixty- four students was interviewed using an oral pretest, post-test, and delayed post-test. Overall, the results support the superiority of the cooperative-mastery learning method over either method alone in promoting the acquisition and retention of economic concepts. Pretest data verified the initial equivalence of groups. The cooperative-mastery learning group outperformed (a) the control group on all post-tests and delayed post-tests and (b) the cooperative learning group on all post-tests and delayed post-tests except the written post-test. By delayed post-test on the oral measure, the cooperative-mastery learning group was also outperforming the mastery learning group. As further evidence of the superiority of the cooperative-mastery learning method, the mean score of the cooperative-mastery learning group was greater than the combined mean scores of the mastery and cooperative learning groups on the oral post-test and delayed post-test. The authors suggest that the cooperative-mastery learning method is in line with current early childhood practices and has the capacity for simultaneously boosting the conceptual development and language development of young children. This capacity is said to stem from the method's provision of (a) specific, positive feedback, (b) a social context for sustained effort and involvement in a topic, (c) child-child communication exchanges, and (d) adult-child communication exchanges.     

浅析比较文学学科定义中的跨越性

兴起于19世纪70年代的比较文学在其发展过程中,国内外学者都表现出了极大的热情,尤其是在比较文学究竞如何定义上做出了积极的探索。国内学界倾向于根据“跨越性”特征来界定比较文学,但对跨越的具体内容却持论不一。     

Comparison of Knowledge and Attitudes Using Computer-based and Face-to-Face Personal Hygiene Training Methods in Food Processing Facilities

ABSTRACT:  Computer-based training is increasingly favored by food companies for training workers due to convenience, self-pacing ability, and ease of use. The objectives of this study were to determine if personal hygiene training, offered through a computer-based method, is as effective as a face-to-face method in knowledge acquisition and improved attitude toward food safety. Employees from four food processing facilities ( n = 94) were randomly assigned to a control group, a face-to-face training group, or a computer-based training group. Evaluation instruments consisted of a pretest and a posttest to measure knowledge gain, a step scale to measure attitude after training and retrospectively before training, and a brief set of interview questions. Results for both treatments and the control group indicated increases in knowledge. Analysis of the posttest scores, when controlling for the pretest scores, indicated the difference was significant ( P ≤ 0.05); however, post hoc analysis did not indicate which treatment was superior. There was a significant increase in attitude scores for both groups using paired t -tests, although the difference between groups was not significant when controlling for attitude scores before training. Issues that may limit application of the technology used in this study include low literacy and language barriers among employees, and time constraints within companies. These and other variables should be taken into account in future research studies addressing comparisons of training methods. This study is the first to demonstrate the effectiveness of computer-based training aimed at food handlers who work in food processing establishments.     

Incorporating Comprehensive Counselling and Guidance Models into School Curricula in Sub-Saharan Africa

There is an increasing body of evidence demonstrating the psychological and social challenges that afflict school-age children in sub-Saharan Africa. In spite of widespread calls to provide counselling and guidance services in schools, efforts at expanding these services remain fragmented and under-resourced. Grounded in both empirical and theoretical literature, this article calls for integration of counselling and guidance through a whole-school approach. Utilizing critical aspects of child and adolescent developmental theory, we summarize the current state of counselling and guidance in the region, evaluate attempts at integration, and propose adoption of a comprehensive guidance and counselling model into school curricula.     

Systematic characterization of degas-driven flow for poly(dimethylsiloxane) microfluidic devices

Degas-driven flow is a novel phenomenon used to propel fluids in poly(dimethylsiloxane) (PDMS)-based microfluidic devices without requiring any external power. This method takes advantage of the inherently high porosity and air solubility of PDMS by removing air molecules from the bulk PDMS before initiating the flow. The dynamics of degas-driven flow are dependent on the channel and device geometries and are highly sensitive to temporal parameters. These dependencies have not been fully characterized, hindering broad use of degas-driven flow as a microfluidic pumping mechanism. Here, we characterize, for the first time, the effect of various parameters on the dynamics of degas-driven flow, including channel geometry, PDMS thickness, PDMS exposure area, vacuum degassing time, and idle time at atmospheric pressure before loading. We investigate the effect of these parameters on flow velocity as well as channel fill time for the degas-driven flow process. Using our devices, we achieved reproducible flow with a standard deviation of less than 8% for flow velocity, as well as maximum flow rates of up to 3 nL∕s and mean flow rates of approximately 1-1.5 nL∕s. Parameters such as channel surface area and PDMS chip exposure area were found to have negligible impact on degas-driven flow dynamics, whereas channel cross-sectional area, degas time, PDMS thickness, and idle time were found to have a larger impact. In addition, we develop a physical model that can predict mean flow velocities within 6% of experimental values and can be used as a tool for future design of PDMS-based microfluidic devices that utilize degas-driven flow.     

Comprehension and content: planning literacy in low socioeconomic and culturally diverse schools

This article defines comprehension as a pragmatic social and intellectual practice. It reviews literature on current approaches to reading instruction for linguistically and culturally diverse and low socioeconomic students, noting the current policy emphasis on the teaching of comprehension as autonomous skills and strategies. The Four Resources model (Freebody and Luke 1990) is used to frame comprehension instruction with an emphasis on student cultural and community knowledge, and substantive intellectual and sociocultural content in elementary and middle school curricula. Illustrations are drawn from research underway on the teaching of literacy in low socioeconomic schools.     

Taking an active role in our pre-service teachers’ overseas teaching experiences: a report on an experiential learning project in China

This report introduces an experiential learning project in a pre-service undergraduate teacher education programme at a major Hong Kong university in which 10 pre-service English language teachers and myself, their teacher educator, participated in a two-week overseas teaching experience in a primary school in Ningbo, China. I report on my experience as a novice teacher educator and the benefit I found in taking an active role in this project.     

Preliminary Validation of the Feelings Experienced in Supervision Scale

The authors conducted a preliminary validation of the Feelings Experienced in Supervision Scale (FESS), with findings supporting a single-factor instrument. Relationships between the FESS and attachment patterns, cognitive distortions, and difficulty with corrective feedback are reported. Implications include emotion-focused supervision to identify thoughts and feelings interfering with supervisees' ability to synthesize corrective feedback.