Cooperative Problem-Solving and Teaching in Preschoolers

The current study investigated the ontogenetic origins of children's skills of cooperative problem-solving in a task involving two complementary roles. Participants were peer dyads of 24, 30, 36, and 42 months of age. Primary dyads were initially presented with an instrumental problem whose solution required them to cooperate by coordinating two complementary actions. To further investigate their understanding of the task, these same dyads were then presented with the same problem but with roles reversed. Finally, after each of these primary participants had demonstrated proficiency in both roles, each was separately paired with a naive peer and given the opportunity to teach the naive partner the task. A clear ontogenetic trend emerged. Even with adult assistance, 24-month-old children never became independently proficient at the task. Thirty-and 36-month-old children became proficient mostly independently, but only relatively slowly and without demonstrating extensive amounts of behavioral coordination or the use of explicitly directive language to facilitate coordination. Although they did show evidence of recognizing when a peer was new to the task, children of this age engaged in little explicit teaching of naive peers. In contrast, 42-month-old children mastered the task much more quickly than the other children, responded much more quickly and accurately when their roles were reversed, coordinated both their actions and language in the task to a much greater extent, and engaged in more explicit teaching of naïve peers. Results are discussed in terms of the developing social cognitive skills that enable children from 2 to 4 years of age to understand other persons as mental agents with whom they may share mental perspectives.     

课外补习、贫富差距的映像与代际变化

本文以武汉市L小学和M大学的调查为基础,说明课外补习与贫富差距之间的联系。各种形式和内容的课外补习既是城乡差距和贫富差距的具体映像,也是维持和推动社会贫富差距的重要力量,使得这一差距具有代际传递特征。在人们越来越关注学校教育公平的今天,课外补习对贫富差距的形成与扩大的消极作用却被忽视;但它所起的维持和传递作用在将来会更大、更顽固。因此。政府要将课外补习限制在一定范围内,并改革正规学校教育系统及人才评估与选拔机制．尽可能地消减这一市场活动的负面作用。     

Selecting and checking a binomial response generalized linear model using phi-divergences

This work introduces specific tools based on phi-divergences to select and check generalized linear models with binary data. A backward selection criterion that helps to reduce the number of explanatory variables is considered. Diagnostic methods based on divergence measures such as a new measure to detect leverage points and two indicators to detect influential points are introduced. As an illustration, the diagnostics are applied to human psychology data.     

物理系学生和数学系学生思维差异分析与普物教学

物理学习与数学有着密切的联系。结合具体的教学例子,分析了物理系学生与数学系学生在普物学习的过程中存在的思维差异,认为应注意到这些差异,对不同学生应采用不同的教学方法,以提高教学质量。     

贺兰山高等真菌区系地理研究

贺兰山高等真菌区系地理成分中,世界性分布属占64.1%、种占19.5,他们多为适应性强的腐生菌类;欧亚北美分布属占35.9%、种占52.7%,未发现热带分布的属或种,充分显示出该地区真菌以北温带分布成分为主的特点;欧亚分布种占11.5%,东亚北美分布种占9.9%,表明该地区真菌区系与欧洲、北美洲的密切联系;中国&日本分布种占3.1%,可见本地区和日本在真菌区系上也有着联系;本地区特有成分较少,但从贺兰山特殊的地理位置、相对孤立的山体和复杂的地形分析,随研究工作的深入,很可能有一些山的分布的特有成分被发现.贺兰山真菌区系成分与邻近的内蒙古大青山相比较,共有种多达57种,而与地处亚热带向热带过渡的湖南莽山相比较,共有种仅有12种,更进一步说明本地区深居北温带,真菌区系以泛北极成分为主的特色.     

Adventures in policy modeling! Operations research in the community and beyond

The literature describing operations research in the community is somewhat of a puzzle. On the one hand, several authors have denigrated the use of traditional operations approaches in addressing community problems, yet several studies document successful applications. Arguing that the operations research mindset is itself a great strength, we will review several examples where operations research methods have been employed creatively to the benefit of the community and beyond.     

分层教学在职业学校数学教学中的应用探索

为了更好地提高职业学校数学课的教学质量,针对传统数学教学模式在目前教学中出现的诸多问题,我们在职业学校数学教学中采用＂分层次＂的教学法进行实验和研究,结果发现,＂分层次＂教学法不仅有利于提高学生学习的积极性、主动性和创造性,有利于培养学生学习兴趣和自我锻炼能力,有利于学生比较牢固地掌握知识和技能,同时,这种方法还为学生终身学习奠定了良好的基础。