大班幼儿数学区域活动中专注力现状及特点分析

专注力是幼儿重要的学习品质,幼儿在数学活动中的投入程度会影响其早期数学经验的习得。以数学区域为媒介,运用 观察法对60 名幼儿独自与合作活动中专注力的思考、伴随语言、抗干扰与注意分散行为进行统计,并结合访谈法收集质性资 料。研究发现：幼儿专注力总体表现较好;存在显著性别差异,女孩伴随语言能力均高于男孩,男孩专注的消极行为则多于女 孩;情境差异中,独自活动产生更多与材料互动的思考行为,共同操作时有声语言的频次更高。     

Predictability of designs which adjust for imbalances in prognostic factors

Minimisation is a method often used in clinical trials to balance the treatment groups with respect to some prognostic factors. In the case of two treatments, the predictability of this method is calculated for different numbers of factors, different numbers of levels of each factor and for different proportions of the population at each level. It is shown that if we know nothing about the previous patients except the last treatment allocation, the next treatment can be correctly guessed more than 60% of the time if no biased coin is used. If the two previous assignments are known to have been the same, the next treatment can be guessed correctly around 80% of the time. Therefore, it is suggested that a biased coin should always be used with minimisation. Different choices of biased coin are investigated in terms of the reduction in predictability and the increase in imbalance that they produce. An alternative design to minimisation which makes use of optimum design theory is also investigated, by means of simulation, and does not appear to have any clear advantages over minimisation with a biased coin.     

Optimal block designs for three treatments when observations are correlated

E$E$-optimal designs for comparing three treatments in blocks of size three are identified, where intrablock observations are correlated according to a first order autoregressive error process with parameter ρ∈(0,1)$\rho \in (0,1)$. For number of blocks b   of the form b=3n+1$b=3n+1$, there are two distinct optimal designs depending on the value of ρ$\rho$, with the best design being unequally replicated for large ρ$\rho$. For other values of b$b$, binary, equireplicate designs with specified within-block assignment patterns are best. In many cases, the stronger majorization optimality is established.     

On empirical likelihood for semiparametric two-sample density ratio models

We consider estimation and test problems for some semiparametric two-sample density ratio models. The profile empirical likelihood (EL) poses an irregularity problem under the null hypothesis that the laws of the two samples are equal. We show that a dual form of the profile EL is well defined even under the null hypothesis. A statistical test, based on the dual form of the EL ratio statistic (ELRS), is then proposed. We give an interpretation for the dual form of the ELRS through φ$\phi$-divergences and duality techniques. The asymptotic properties of the test statistic are presented both under the null and the alternative hypotheses, and approximation of the power function of the test is deduced.     

数学教学中培养学生创新能力的实践与思考

本文立足数学教学实践,提出了注重培养学生的创新能力及实践能力的主张,并强调要引导学生加深对创新概念的理解和认识.     

Statistical analysis for rounded data

When random variables do not take discrete values, observed data are often the rounded values of continuous random variables. Errors caused by rounding of data are often neglected by classical statistical theories. While some pioneers have identified and made suggestions to rectify the problem, few suitable approaches were proposed. In this paper, we propose an approximate MLE (AMLE) procedure to estimate the parameters and discuss the consistency and asymptotic normality of the estimates. For our illustration, we shall consider the estimates of the parameters in AR(p)$\mathit{AR}(p)$ and MA(q)$\mathit{MA}(q)$ models for rounded data.     

浅析数学建模在高师数学教育中的作用

文章从教学内容、教学方式、教学手段三方面论述了数学建模在推动数学教学改革中的作用及对激发学生学习兴趣、培养学生能力方面的作用。     

关于中小学减负政策实施的反思与改进——基于“剧场效应”的视角

减负政策的实施一直无法走出没能给学生减负反而增负的"迷阵"。这一问题也成为多年来基础教育研究的热点。"剧场效应"揭示个人寻求自身利益最大化而导致集体利益受损的现象本质。依据诺斯对于制度的划分，从减负政策执行的角度来分析政策实施乏力的原因在于：正式制度层面减负政策的执行导致学生在校时间的减少和学生校外自由时间的增多；非正式制度层面社会认可的行为准则与自我实施的行为标准促进补习"剧场效应"的生成。由此，补习"剧场效应"削弱学校发展"全人教育"功能，维持社会不平等代际传递，增加家庭经济压力。鉴于此，破解补习"剧场效应"的重点在于加大政府作为"剧场管理员"的监管力度，提高学校教育质量，促进教育评价体系的完善。     

A Theoretical Model of Intergenerational Tutoring

ABSTRACT

This paper presents a psychological model of intergenerational tutoring, which applies to both helpers and those who are helped. It shows how fully formed intergenerational tutoring can operate, and can thus identify gaps. These gaps can be addressed and some filled by learning partners, perhaps with help from professionals or more experienced partners. Sixteen elements are identified, the first two in sequence, then five with equal weight, then nine in sequence. The model is a template for monitoring intergenerational interactions as they are happening. It also forms a tool for self-assessment/peer assessment. Additionally, it may help in designing intergenerational tutoring.