Why is S a Biased Estimate of σ?

This article outlines an experiment that leads one to discover and verify that S is a biased estimator of σ.     

Multicultural visions in early reading classrooms: Implications for early childhood teacher educators

Abstract

Teachers and teacher educators are faced with an urgent responsibility to support the learning of an increasingly diverse population of young children. Based on the sociocultural perspective of reading, a literature‐based approach is outlined for early reading teachers. The implications of this approach to teacher education programs are further discussed from the author's own experiences of transmitting multicultural visions to preservice teachers in a multicultural course and a literacy method course she taught. The author maintains that teacher educators are in a unique position to help early childhood teacher candidates nurture multicultural visions in their teacher education programs today, and carry these visions to their future early reading classrooms tomorrow. © 2005 Elsevier Inc. All rights reserved.     

冲突性话语中的语用缓和研究概述

本文是有关冲突性话语中的语用缓和研究概述。首先讨论冲突性话语的回应类型,然后在回顾国内外学者相关研究的基础上,总结言谈中关于直接反对、批评、不同意的缓和性回应类型的研究比较少,存在一定研究空间,这也就是本文的研究意义所在。如何缓和言语交际、避免言语冲突对人与人之间的社会交往有着积极深远的影响,笔者希望这些语用缓和的研究概述能够引起更多的人对这方面的关注。     

Mitigation of Blast Effects on Aluminum Foam Protected Masonry Walls

Terrorist attacks using improvised explosive devices (IED) can result in unreinforced ma-sonry (URM) wall collapse. Protecting URM wall from IED attack is very complicated. An effective solution to mitigate blast effects on URM wall is to retrofit URM walls with metallic foam sheets to absorb blast energy. However, mitigation of blast effects on metallic foam protected URM walls is currently in their infancy in the world. In this paper, numerical models are used to simulate the per-formance of aluminum foam protected URM walls subjected to blast loads. A distinctive model, in which mortar and brick units of masonry are discritized individually, is used to model the perform-ance of masonry and the contact between the masonry and steel face-sheet of aluminum foam is modelled using the interface element model. The aluminum foam is modelled by a nonlinear elas-toplastic material model. The material models for masonry, aluminum foam and interface are then coded into a finite element program LS-DYNA3D to perform the numerical calculations of response and damage of aluminum foam protected URM walls under airblast loads. Discussion is made on the effectiveness of the aluminum foam protected system for URM wall against blast loads.     

Risk identification and risk mitigation during metro station construction by enlarging shield tunnel combined with cut-and-cover method

Constructing a metro station by enlarging shield tunnels combined with a mining/cut-and-cover method provides a new method to solve the contradictions of construction time limits of shield tunnels and stations. As a new-style construction method, there are several specific risks involved in the construction process. Based on the test section of Sanyuanqiao station on Beijing metro line 10, and combined with the existing methods of risk identification at present, including a review of world-wide operational experience of similar projects, the study of generic guidance on hazards associated with the type of work being undertaken, and discussions with qualified and experienced staff from the project team, etc., the specific risks during the construction process of the metro station constructed by enlarging shield tunnels combined with the cut-and-cover method are identified. The results show that the specific risks mainly come from three construction processes which include constructing upper enclosure structures, excavating the soil between shield tunnels and demolishing shield segments. Then relevant risk mitigation measures are put forward. The results can provide references for scheme improvement and a comprehensive risk assessment of the new-style construction method.     

The State of the Literature on Student Evaluations of Teaching and an Exploratory Analysis of Written Comments: Who Benefits Most?

The purpose of this exploratory analysis is to review the state of the literature on student evaluations (SEs) of teaching and examine to what extent an instructor's race/ethnicity influences student's qualitative comments. Also, does the intersection of race and gender influence student's qualitative comments on SEs? Utilizing an online survey distributed among various organizational listserv in the discipline of Political Science, this study highlights written comments received on SEs by faculty generally. Additionally, we hope to contribute findings that support how negative comments may affect faculty of color and women.     

Sources of bias in special needs provision in mainstream primary schools: evidence from two British cohort studies

This study examines inequality during late childhood in children's access to special needs help in mainstream primary schools using data from two British cohorts: the National Child Development Study (NCDS) and the 1970 British Cohort Study (BCS70). It explores the source of any biases in the provision of special help using measures of individual gender, attainment and psychosocial adjustment; family social class; school composition; and education regions. Pervasive gender bias was found both in the identification of children with special needs and in the provision of help to children with special needs. There were more children from manual homes receiving help in school than children from professional homes, but when reading, mathematics and psychosocial adjustment scores were taken into account, the gradient reversed, so that children from professional homes were more likely to be getting help. The influence of the school's composition showed the same reversal. Once test scores were considered, schools with a greater proportion of above average children were more likely to be able to provide help for those with special needs than schools with a greater proportion of children with problems. Regional variation suggests that areas in southeast England are better funded than average, while areas of deprivation are not provided with sufficient resources to meet their children's needs.     

The impact of a team's aggressive reputation on the decisions of association football referees

It has been suggested that individuals may use heuristic methods of reasoning and rely on schemata when a quick decision is necessary. Accordingly, it is possible that decisions made by sport officials may be influenced by prior knowledge they have about teams they are officiating. The aim of the present study was to determine whether sport officials are more likely to penalize individuals who participate in a team with an aggressive reputation. In a balanced design, 38 football referees were randomly assigned to either an experimental or control group and were presented with the same 50 video clips of incidents from football games, all involving a team in a blue strip ('blue team'). The incidents were categorized before the study by five experienced referees into fouls committed both by, and against, the blue team, where all participants agreed that a foul had been committed (certain incidents), disagreed it was a foul (uncertain incidents) or agreed that there was no foul (innocuous incidents). Both groups received written instructions before the task; in addition, the experimental group was informed that the blue team present in all of the clips had a reputation for foul and aggressive play. For each incident, the participants were required to indicate what action they would engage in if refereeing the game. Although there was no difference in the number of decisions made, the experimental group awarded significantly more red and yellow cards against the blue team both overall and for the 'certain' incidents. It is suggested that prior knowledge may impact referees' behaviour in a laboratory setting, although future research should explore whether a similar effect is observed in the behaviour of referees during football matches.     

Decision-Making Groups Attenuate the Discussion Bias in Favor of Shared Information: A Meta-Analysis

Groups often focus their discussions on information that all members know at the outset. To test how robust the sampling advantage for shared information is, a meta-analysis was conducted. The analysis integrated findings from 20 publications (45 independent effects), in which information sharedness was manipulated. Groups discussed more shared than unshared information overall. However, the observed sampling advantage was smaller than expected. Groups attenuated the discussion bias in particular when they had to choose among a small number of decision alternatives and when they had less than 30 minutes discussion time. Moreover, groups performing a hidden-profile task tended to display a smaller discussion bias than groups performing tasks with equally attractive alternatives.