A behavioural dynamic model of the relative age effect

Abstract

The relationship between date of birth and success in a variety of sports, including hockey, is well established. This phenomenon is known as the relative age effect (RAE). We model the RAE in Canadian youth hockey as a positive feedback loop where an initial age advantage is reinforced through additional training and playing opportunities based on perceived skill superiority. The same causal mechanism leads to a higher quit rate for relatively younger players. Our model effectively replicates the birth month distribution of Canadian National Hockey League players (R² = 86.79%) when driven by Canadian birth distributions. We use this model to evaluate three policies that aim to lessen the RAE. All of the policies reduce the RAE with a significant delay. The most effective policy is a combination of providing additional support to age disadvantaged children and rotating the cut-off date for youth leagues between January 1st and July 1st annually. In equilibrium, this approach leads to a 96% reduction in the RAE compared to the base case.     

Within‐High‐School Versus Across‐High‐School Scaling of Admissions Assessments: Implications for Validity and Diversity Effects

Previous research has established that SAT scores and high school grade point average (HSGPA) differ in their predictive power and in the size of mean differences across racial/ethnic groups. However, the SAT is scaled nationally across all test takers while HSGPA is scaled locally within a school. In this study, the researchers propose that this difference in how SAT scores and HSGPA are scaled partially explains differences in validity and subgroup differences. Using a large data set consisting of 170,390 students each of whom matriculated at one of 114 separate colleges, the researchers find that awarding SAT scores by ranking SAT within a high school generally results in substantial reduction in the size of subgroup mean differences for this predictor. However, validity for predicting first‐year GPA is also reduced by a small amount. Conversely, placing HSGPA onto a nationally normed metric through the use of multiple regression procedures results in a moderate increase in the size of subgroup mean differences, while also producing a small increase in validity. Taken together, these findings suggest that differences in predictor scaling can partially explain differences in the size of subgroup mean differences between HSGPA and SAT scores and have implications for predictive power.     

New settings and changing norms for principal development

During the 1980s, the field of professional development for school leaders expanded in numerous respects: raw enrollment figures, intensity and breadth of participation, types and number of in-service providers, approaches to program governance, variety of curricular and instructional approaches. Previous analyses have compared this new inservice movement with traditional efforts to prepare school administrators. Typically these comparisons have sought to highlight differences between pre- and post-1980 development efforts, thereby unintentionally masking important organizational and programmatic differences among the emergent programs. This article focuses specifically on describing and assessing the range of variation among the predominant professional development programs born in the 1980s. We highlight divergent trends with respect to the organizational processes and program content that characterize these programs and identify their varying potential for reaching competing policy goals. Finally, we suggest implications for both policy and practice in the field of administrative development.     

排名的困境

分析了大学排行榜产生的原因,指出了大学排名活动中存在的问题,如评估指标的选取、大学的不同定位等,进而指出世界范围内的排名活动会加大英语国家大学的强势,不利于发展中国家大学的发展,并认为大学排名活动应以准确的评估和科学的指标体系作为基础。     

Relationships between student characteristics and self‐, peer and tutor evaluations of oral presentations

There are many influences on how assessors grade themselves and others. Oral presentations are useful for exploring such factors in peer, self‐ and tutor marked assessments, being rapidly completed and assessed, commonly used in HE and very difficult to anonymize. This opportunistic study examined the effects of gender and level of attainment on the triangulation of marks awarded to student presenters. Grades generated by peer assessment were associated more strongly with tutor‐awarded marks than those from self‐assessment. For self‐assessment there was a strong effect of gender (female students undervalued their performance compared with tutor grades). Peer assessment produced higher marks than from tutors, perhaps because of the close‐knit community developed during residential courses. For tutor marks, the greatest variability was at the lower end of the scale, whereas peer assessors were most variable when marking students who self‐evaluated or peer assessed highly. Students awarded a narrower range of marks to peers compared with tutors, but when self‐assessing used a larger range. Presentations by students who admitted to little sleep the night before received lower grades from both peers and tutors, but this was not reflected by self‐assessments, suggesting they were unaware of their poorer performances. Sessions with fewer talks (four rather than seven) reduced the ‘dip’ in marks previously observed in the middle of sessions. Findings are discussed in the context of bias in this mode of assessment.     

报纸公信力的定义和测量:指标建立

根据《韦伯新学院词典》的注释,"令人可信的(to be credible)"被定义为:能够提供一些合乎逻辑的,使人信服的理由。然而,一些报社的编辑表达了另外的思考。他们认为,"公信力"这个概念应该增加一个额外的维度,即报纸在社区中保持和谐和领导地位。     

“I Can Air My Feelings Instead of Eating Them”: Blogging as Social Support for the Morbidly Obese

The morbidly obese, defined as people who are 100 pounds or more overweight, are the fastest growing population among the obese. They often live with health risks, face discrimination, and lack traditional social support. This article explores the use of weight loss blogs by the morbidly obese (N = 50) and argues that blogging provides invaluable computer-mediated social support for them in four ways: (a) it allows for empathy; (b) it ensures accountability to others; (c) it provides venting and advice seeking; and (d) it shares validation of the weight loss experience. Additionally, the article argues that social support scholars must move beyond chat rooms and message boards as media and explore more media-rich environments such as blogging and social networks.     

The Media Audience

Philip Zimbardo and Ebbe B. Ebbeson's Influencing Attitudes and Changing Behavior: A Basic Introduction to Relevant Methodology, Theory, and Applications. (Addison-Wesley, $2.25 paper)