The use of minimization to form comparison groups in educational research

Randomized controlled trials in educational research tend to be small. Small trials can have large, chance, imbalances in important covariates. For studies with sample sizes greater than 50, chance imbalances can be corrected using analysis of covariance; for small trials, however, statistical power is maximized if the trial is balanced and analysis of covariance is used in the analysis. The aim of the present study was to discuss methods of improving covariate balance in trial design and to demonstrate the method of minimization. Using an exemplar of a cluster or class‐randomized trial with 29 classes, we employed minimization to achieve covariate balance. Minimization achieved good balance on four prognostic variables. Many trialists in education use restricted forms of allocation, including pairing or stratified randomization. These approaches have disadvantages. Another approach rarely used in educational research is minimization. Minimization uses a simple arithmetic algorithm to produce balanced groups across a number of important covariates and should be more widely used in educational and psychological research.     

Progress in the past decade: an examination of the precision of cluster randomized trials funded by the U.S. Institute of Education Sciences

ABSTRACT

This article examines the statistical precision of cluster randomized trials (CRTs) funded by the Institute of Education Sciences (IES). Specifically, it compares the total number of clusters randomized and the minimum detectable effect size (MDES) of two sets of studies, those funded in the early years of IES (2002–2004) and those funded in the recent years (2011–2013). Overall, the average precision in terms of MDES of studies in the recent cohort was more than double that of the early cohort (i.e. 0.48 compared to 0.23). The findings suggest a consistent and substantial increase in the precision of CRTs funded by IES in the past decade which is a critical step towards designing studies that have the potential to yield high-quality evidence about the effectiveness of educational interventions.     

我国民事诉讼三审终审制度的构建

审级制度是为法院的公正裁判服务的。它包括法院定位、受案范围的制度层面；越级上诉、强制代理的运作层面；三审终市制与再审的关系层面等。随着我国民事审判方式改革的深入，对审级制度进行与时俱进的改革显得尤为迫切。     

One-Parameter Item Response Theory Models for Psychomotor Tests Involving Repeated,Independent Attempts

Abstract

Three one-parameter item response theory models are given as viable models that describe the observed score probabilities of an examinee who takes a multiple attempts, single-item test of a psychomotor skill. These models include the Binomial Trials Model, the Poisson Counts Model, and the Inverse Binomial Model. The paper presents these models and offers suggestions for their estimation and subsequent use in the assessment of psychomotor behavior.     

A Randomized Experiment of a Cognitive Strategies Approach to Text-Based Analytical Writing for Mainstreamed Latino English Language Learners in Grades 6 to 12

Abstract

This study reports Year 1 findings from a multisite cluster randomized controlled trial of a cognitive strategies approach to teaching text-based analytical writing for mainstreamed Latino English language learners (ELLs) in 9 middle schools and 6 high schools. There were 103 English teachers stratified by school and grade and then randomly assigned to the Pathway Project professional development intervention or control group. The Pathway Project trains teachers to use a pretest on-demand writing assessment to improve text-based analytical writing instruction for mainstreamed Latino ELLs who are able to participate in regular English classes. The intervention draws on well-documented instructional frameworks for teaching mainstreamed ELLs. Such frameworks emphasize the merits of a cognitive strategies approach that supports these learners’ English language development. Pathway teachers participated in 46 hrs of training and learned how to apply cognitive strategies by using an on-demand writing assessment to help students understand, interpret, and write analytical essays about literature. Multilevel models revealed significant effects on an on-demand writing assessment (d = .35) and the California Standards Test in English language arts (d = .07).     

United States National Library of Medicine Drug Information Portal

The Drug Information Portal is a free Web resource from the National Library of Medicine (NLM) that provides a user-friendly gateway to current information for more than 15,000 drugs. The site guides users to related resources of NLM, the National Institutes of Health (NIH), and other government agencies. Current drug-related information regarding consumer health, clinical trials, AIDS, MeSH pharmacological actions, MEDLINE/PubMed biomedical literature, and physical properties and structure is easily retrieved by searching on a drug name. A varied selection of focused topics in medicine and drugs is also available from displayed subject headings. This column provides background information about the Drug Information Portal, as well as search basics.     

提高试举成功率是举重比赛取胜的关键因素

运用文献资料法等方法,参加世界举重锦标赛的对中国男队和参加全国青年、省少年男子举重锦标赛的男运动员进行了统计分析.结果表明我国男运动员在国内外比赛中试举成功率普遍偏低.影响试举成功率的因素有赛前训练、减体重、准备活动和选定试举重量等.建议采取有针对性的措施,以提高试举成功率.     

男子跳远运动员不同跳次中摆动腿摆动对速度变化特征的影响

采用现场定点高速摄像及数理统计法，对男子跳远运动员起跳阶段不同时相、身体重心水平速度和垂直速度的变化与起跳缓冲、蹬伸阶段摆动腿角速度和两大腿夹角变化进行比较分析。结果表明：成绩较好者，缓冲阶段身体重心水平速度减小值略大，垂直速度的增加值则更大；离板瞬间身体重心水平速度和垂直速度都呈现出相对较大的趋势。     

中国式政策试点与法治理念冲突——基于二胎政策试点

中国的政策之提出,通常是在局部地区首先试点,试点地区和内容均缺乏公众参与机制和民意支持。法治理念包括机会平等、追求一般意义上的公平正义、尊重民意、程序理想等内容,以二胎政策试点为代表的中国式试点与法治理念存在诸多冲突。