Recursive and explicit rules: How can we build student algebraic understanding?

Differing perspectives have been offered about student use of recursive and explicit rules. These include: (a) promoting the use of explicit rules over the use of recursive rules, and (b) encouraging student use of both recursive and explicit rules. This study sought to explore students’ use of recursive and explicit rules by examining the reasoning of 25 sixth-grade students, including a focus on four target students, as they approached tasks in which they were required to develop generalizations while using computer spreadsheets as an instructional tool. The results demonstrate the difficulty that students had moving from the successful use of recursive rules toward explicit rules. In particular, two students abandoned general reasoning, instead focusing on particular values in an attempt to construct explicit rules. It is recommended that students be encouraged to connect recursive and explicit rules as a potential means for constructing successful generalizations.     

化学教师的科学素养

正在进行的基础教育课程改革以培养学生的科学素养为主旨，而教师的科学素养是课程改革成功的重要因素．本文就化学教师的科学素养的构成谈个人的认识．     

Chinese Statistical Parser Based on Semantic Dependencies

IntroductionMuch recent research on statistical parsers hasfocused on English.English has a large syntacticcorpus,the English UPenn Treebank.Everysentence in this corpus corresponds to a syntacticstructure[1] .Many kinds of parsers for Englishhave been developed based on this corpus[2 4 ] .Thestructure of the Chinese language is quite differentfrom English and there have been only a fewefforts to build syntactic corpora in recent years.Two syntactic corpora were just announced in2 0 0 0 ,t…     

试论反例的教学功能

该文通过对高等数学教学中构造反例的教学功能的阐述,说明了构造反例对强化数学知识的理解掌握,思维定势的克服,学生发散思维能力和创造力的培养,甚至课堂教学质量的提高均有着不可低估的作用。     

干涉条纹识别的自适应视觉基元匹配法

通过对光学干涉条纹灰度分布规律的分析，针对其全场灰度极值分布不均匀的，本文根据自适应原理，提出了用于确定条纹方向的自适应视觉基元匹配法，并且采用二维灰度场的方向导数确定灰度的极值位置，使得对于干涉条纹光学中的识别达到了很好的效果。     

Students’ ways of understanding a proof

We present a model for describing the growth of students’ understandings when reading a proof. The model is composed of two main paths. One is focused on becoming aware of the deductive structure of the proof, in other words, understanding the proof at a semantic level. Generalization, abstraction, and formalization are the most important transitions in this path. The other path focuses on the surface-level form of the proof, and the use of symbolic representations. At the end of this path, students understand how and why symbolic computations formally establish a claim, at a syntactic level. We make distinctions between states in the model and illustrate them with examples from early secondary students’ mathematical activity. We then apply the model to one student’s developing understanding in order to show how the model works in practice. We close with some suggestions for further research.     

文化教学中的文化理解

通过对云南某新建地方师范院校英语专业化教学现状的调查分析，论证了目前高等学校英语专业化教学注重目的语化知识的传播，忽视跨化交际技能力的培养。要培养具有跨化交际能力的外语人才，语言教学中应重视化教学。化教学应超越以积累化知识为目的的知识传播，通过化意识培养达到对化的理解。     

人口因素是重要的国情

本文论适中国人口因素的重要特点，对马克思主义中国化的影响，以及结合历史经验教训在认识和把握人口因素中应注意的问题。     

The powers and pitfalls of algorithmic knowledge: a case study

This study examines one child's use of computational procedures over a period of 3 years in an urban elementary school where teachers were using a standards-based curriculum. From a sociocultural perspective, the use of standard algorithms to solve mathematical problems is viewed as a cultural tool that both enables and constrains particular practices. As this student appropriated and mastered procedures for addition, subtraction, multiplication and division, she could solve problems that involved fairly straightforward computations or where she could easily model the action to determine an appropriate computation. At the same time, her use of these algorithms, along with other readily available tools, such as her fingers or multiplication tables, constrained her ability to reflect on the tens-structure of the number system, an effect that had serious consequences for her overall mathematical achievement. The results of this study suggest that even when not directly introduced, algorithms have such strong currency that they can mediate more reform-oriented instruction.     

精神迷失的踪迹和文学理解的庄严——从《黑魇》看昆明时期的沈从文

以沈从文20世纪40年代的作品《黑魇》为核心,参照同一类型散文作品中的其他几篇,再辅之以同时期的几篇文论,进行文本细读,来理解和叙述沈从文昆明时期的思想重心、感触接点、精神踪迹和文学理解,特别描述出其精神迷失的具体情形,并强调其文学理解的庄严,从而论述沈从文作为一个作家在思想上和文学上的独特性。