二参数逻辑斯蒂模型项目参数的估计精度

项目参数的估计精度对于测验的编制尤其是题库的建立十分重要。目前,国内外对项目参数估计精度的研究,大部分是基于在已知项目参数真值的情况下,运用各种参数估计方法产生新的估计值,再和真值进行偏度(BIAS)和均方根差(RMSE)的比较,从而说明该种估计方法的有效性。但是这种方法不能提供不同的参数真值之间的估计误差的变化规律。为了弥补这一缺陷,本文尝试从项目参数估计信息函数的角度出发研究项目参数的估计精度问题。本研究以二参数Logistic模型作为研究对象,首先定义了项目参数的估计信息函数,然后基于完全随机实验设计,通过模拟研究的方法探索影响项目参数的估计精度的因素,实验共设计了(2×3×2)种情形。研究结果表明：(1)项目参数(a,b)的估计精度均随着被试样本量的增大而提高;(2)被试的能力分布对难度参数的估计精度影响较大,对区分度参数的估计精度影响相对较小;(3)难度参数和区分度参数的估计精度都分别受到参数a和参数b的共同作用。     

The Five-Factor model of personality and work behaviour in Greece

This study explores the validity of the five-factor model of personality (FFM) in occupational settings in Greece, examining its relationship to employees' overall job performance, job satisfaction, organizational citizenship behaviour, and generic work competencies. Two hundred and twenty-seven employees from various Greek SMEs participated in the study completing a personality and a job satisfaction measure. Their supervisors completed three questionnaires assessing their performance and their work competencies. Some of the most significant results of this study were the strong links identified between personality and job satisfaction and the moderating effect of job type on the criterion-related validity of some personality dimensions. These results are discussed in terms of the FFM literature taking into consideration the strong effect of Greek culture. The theoretical and practical implications for research and practice in Greece are also discussed.     

自杀高危人群的识别及预防研究

自杀是由严重心理危机导致的行为.通过描述自杀高危人群存在的时代状况,从社会学与心理-精神病学的维度分析了高危人群的自杀成因,进而对其自杀前的异常言行表现、自杀的方式及当前各种预防措施进行讨论.同时,对中国文化语境下的自杀及其预防展开了反思与展望.     

Support Group Needs for People Living with HIV and AIDS (PLWHA) in Communities around Durban,South Africa

The study constructed a participant centred perspective of what members of a support group for people living with HIV and AIDS (PLWHA) desired from their group meetings. The study sample (n = 34) was from three support groups of PLWHA in a province of South Africa (males = 7, female = 27, mean age = 34.2 years, SD = 6.8 years). Participants completed a brief survey and participated in focus group discussion on views on the ideal support group, actual experience with the support group, and solutions for effective support groups. Findings suggest most members of the support group experienced a high degree of stigma at home and needed a so-called ‘safe space’ to escape to and discuss issues with people experiencing similar problems. Respondents wanted to acquire skills to allow them to help themselves and others in the community. They also desired HIV education so that they could properly understand the virus and help the community understand it to reduce stigma.     

The development of work discussion groups in educational settings

This paper describes the application and development of the work discussion method within educational settings. In the first section of the paper, I outline some key contextual factors that are important to consider when setting up work discussion groups within schools. A number of case examples are then described, illustrating a range of central issues that can emerge. By developing a deeper understanding about the meaning of behaviour and the emotional factors that impact on teaching and learning, I hope to demonstrate how work discussion groups can help teachers to develop their capacity to manage the challenges of their work, role and relationships with pupils. More broadly, I hope to illustrate how these groups can help to promote a learning environment for all, in which development and growth is promoted at a personal, professional and whole school level.     

One Parent-Child Activity Group

Abstract

The framework that the author developed for parent-child activity groups is described. This is followed by “snapshots” of a group session to enhance the readers' understanding of the framework. Excerpts of the author's logs from her participant observation of the parent-child activity group that she studied are organized sequentially to provide examples of each part of a parent-child activity group session.     

Exploring What Was Missing in One Parent-Child Activity Group

Abstract

Barriers to parent-child interaction that arose in the parent-child activity group studied by the author are discussed. An analysis of what factors within the group may have led to the barriers is provided so that readers can consider how to minimize barriers to parent-child interaction in similar groups.     

Children’s social cognition about proactive aggression

In this study, 6- and 9-year-old children (N = 258) observed two instances of proactive aggression (one relational and the other direct aggression) that were committed by members of a group toward out-group members. Participants were either members of the group or independent observers. Analyses of participants’ social cognition about the aggressor and the aggression (cause of aggression, moral judgment of aggression, attitudes toward the aggressor, and exclusion of the aggressor) indicated that, overall, group members were more positive toward aggressors than were independent observers. Although intergroup competition was perceived to be the cause of the aggression, participants disapproved of both types of aggression (especially direct aggression), disapproval increased with age, and girls disapproved of relational aggression more than did boys. Group members’ social cognition about the aggressor and the aggression comprised a coherent cognitive process for both types of aggression, but the observers’ process was simpler and differed by aggression type.     

Witness Vetting: What Determines Detectives' Perceptions of Witness Credibility?

During the course of a criminal investigation witness vetting, a detective's process of determining the credibility and weight of witness information, can lead to errors in an investigation that can go virtually unchallenged. Witness confidence, opportunity to view, and type of information proffered were examined in relation to detective inferences about witness reliability, accuracy, and probable cause to arrest. Experiment 1 involved 39 sworn law enforcement officers, and experiment 2 involved 43 sworn law enforcement officers and 86 mock detectives. Participants viewed a digital recording depicting a witness describing a gas station robbery (Experiment 1) or a campus mugging (Experiment 2). Witness confidence and detectives' inferences about culprit information influenced the vetting process and lent credibility to a confident witness whose accuracy was objectively unknown. Furthermore, the evidence indicates that sworn law enforcement are comparable with untrained observers in their use of social inference cues (i.e. confidence) in determining witness credibility; however, social inference can be assuaged by the rational, rule‐governed, decision framework established for witness vetting. Social inference processes inherent in the detective‐witness dyad is influenced by legal procedures in vetting witness information. Copyright © 2013 John Wiley & Sons, Ltd.     

Key challenges in tram/streetcar driving from the tram driver’s perspective – A qualitative study

Tram drivers have a difficult task in controlling one of the heaviest vehicles on the road whilst negotiating a complex road environment with multiple road users. Like all public transport drivers, tram drivers need to ensure passenger safety and to run on time. However, very little research has been conducted evaluating tram driving tasks and even less on evaluating tram drivers opinion on how other road users are affecting tram road safety. Therefore, the aim of this study is to investigate the key tram driving challenges, to identify the key road user factors affecting tram road safety as well as to explore the potential safety improvement initiatives on tram routes from the tram drivers’ viewpoint. The study incorporated five focus groups involving thirty tram drivers in Melbourne. The key themes emerged inductively from focus groups were identified through a data coding process. Outcomes of the focus groups revealed seven major challenges in tram driving: ensuring safety for all people in and around the tram, pressure for running on-time, maintaining constant concentration on roads, predicting other road users’ behavior in advance to avoid any crash incident, preventing passenger falls on board, accepting the operational constraints of trams and managing fatigue workloads. Tram drivers identified that other road users are unaware of safety issues around trams, have a poor understanding of road rules about driving with trams and often violate road rules around trams, and they mentioned this road user behaviors as the key challenges for safe tram driving. Tram drivers proposed rendering greater law enforcement on the tram network to penalize road users who are violating road rules around trams, introducing more safety campaigns and safety education to increase awareness among road users to improve tram road safety. Findings of this research enhance understanding of tram driving challenges, provide an in-depth knowledge of road user factors affecting tram road safety and suggest effective planning strategies for transit agencies to improve road safety.