A series of lower bounds to the reliability of a test

Two well-known lower bounds to the reliability in classical test theory, Guttman's ₂ and Cronbach's coefficient alpha, are shown to be terms of an infinite series of lower bounds. All terms of this series are equal to the reliability if and only if the test is composed of items which are essentially tau-equivalent. Some practical examples, comparing the first 7 terms of the series, are offered. It appears that the second term (₂) is generally worth-while computing as an improvement of the first term (alpha) whereas going beyond the second term is not worth the computational effort. Possibly an exception should be made for very short tests having widely spread absolute values of covariances between items. The relationship of the series and previous work on lower bound estimates for the reliability is briefly discussed.The authors are obliged to Henk Camstra for providing a computer program that was used in this study.     

Changes in the parental bond and the well-being of adolescents and young adults

Changes in the parental bond and the well-being of adolescents and young adults were investigated in this longitudinal study among Dutch youngsters aged 12 to 24 years (their ages ranged from 15 to 27 years when they were assessed for the second time three years later, and from 18 to 30 years when assessed for the third time). A total of 1,078 adolescents/young adults (459 males and 619 females) participated. We found a curvilinear pattern in the bond between daughters and their parents. For most of the boys, there was a deterioration in the parental bond during the transition from early to midadolescence, which does not subsequently improve. The general conclusion, however, is that adolescents and young adults maintain a rather good and reasonably stable relationship with their parents. Parents prove to be of lasting importance for the well-being of their growing children. For adult children, the parental bond appears to be as important for their well-being as having a partner or a best friend.     

Explaining Differences in Philanthropic Behavior Between Christians,Muslims, and Hindus in the Netherlands

Using survey data from the Netherlands, we find that Muslims have relatively high levels of religious philanthropic behavior and relatively low levels of secular philanthropic behavior, whereas Hindus have relatively low levels of religious philanthropic behavior and higher levels of secular philanthropic behavior. Results indicate that the community explanation and the conviction explanation of the relationship between religion and philanthropic behavior are both valid to some extent when it comes to differences in philanthropic behavior between Christians, Muslims, and Hindus. In addition, we find a relationship between group orientation in worship rituals on the relation between religion and philanthropic behavior. The more group-oriented the worship rituals, the stronger the relation between religion and philanthropic behavior. The results suggest that Durkheim’s theory (La Suicide: Etude de Sociologie. Presses Universitaires de France, Paris, 1897) may only be valid in a Christian context.     

Management of Employability in The Netherlands

This article explores the question how companies can create a different basis for security for their employees now that job security has increasingly become a thing of the past? An answer to this question is to create a new secure base by developing the employability of workers by sustaining and developing opportunities for work in the future. Promoting employability is part of a new psychological contract between employer and employee, whereby both are responsible for maintaining the employment situation. The employability of employees is determined by their actual know-how and skills; their willingness to be mobile and their knowledge of the labour market. Although the development of employability is not only a matter for labour organizations (branch organizations, the government, and employers' representatives and unions have to do their part too), we focus primarily on the policy that organizations can set out. Policymakers have to answer the following questions: (1) Is it necessary to develop the external or internal employability of employees? (2) For which category is it in particular necessary? (3) If employability does not take place automatically, is this because employees do not want this, or because they cannot do this? Or is it restricted by organizational aspects? Each of these questions will be discussed in this article.     

Bullying as strategic behavior: relations with desired and acquired dominance in the peer group

To examine whether bullying is strategic behavior aimed at obtaining or maintaining social dominance, 1129 9- to 12-year-old Dutch children were classified in terms of their role in bullying and in terms of their use of dominance oriented coercive and prosocial social strategies. Multi-informant measures of participants’ acquired and desired social dominance were also included. Unlike non-bullying children, children contributing to bullying often were bistrategics in that they used both coercive and prosocial strategies and they also were socially dominant. Ringleader bullies also expressed a higher desire to be dominant. Among non-bullying children, those who tended to help victims were relatively socially dominant but victims and outsiders were not. Generally, the data supported the claim that bullying is dominance-oriented strategic behavior, which suggests that intervention strategies are more likely to be successful when they take the functional aspects of bullying behavior into account.     

Parental strategies and trajectories of peer victimization in 4 to 5 year olds

This study was designed to examine how parental strategies contribute to explaining trajectories of peer victimization in young children. A total of 73 4 and 5 year old children identified as victims of peer aggression in the fall semester and their parents were recruited from 46 classrooms in 18 schools in the Netherlands. All children were followed-up twice in order to determine for whom victimization was stable. Hypothetical vignettes describing various forms of victimization were presented to one parent of each child in order to assess parental responses to victimization events. Findings indicated that autonomy supporting and autonomy neutral strategies were associated with a decrease of victimization in the first semester of the school year. No protective effects were found in the second semester. Autonomy undermining strategies were not related to the course of peer victimization. These findings underscore the importance of joint and coordinated efforts of teachers and parents as partners in supporting victimized young children at school.     

Computational aspects of the greatest lower bound to the reliability and constrained minimum trace factor analysis

In the last decade several algorithms for computing the greatest lower bound to reliability or the constrained minimum-trace communality solution in factor analysis have been developed. In this paper convergence properties of these methods are examined. Instead of using Lagrange multipliers a new theorem is applied that gives a sufficient condition for a symmetric matrix to be Gramian. Whereas computational pitfalls for two methods suggested by Woodhouse and Jackson can be constructed it is shown that a slightly modified version of one method suggested by Bentler and Woodward can safely be applied to any set of data. A uniqueness proof for the solution desired is offered.The authors are obliged to Charles Lewis and Dirk Knol for helpful comments, and to Frank Brokken and Henk Camstra for developing computer programs.     

Correlation coefficients for more than one scale type: An alternative to the Janson and Vegelius approach

Janson and Vegelius have recently suggested a family of correlations for variables of mixed scale types, including nominal scales. The resulting correlations areE-coefficients, which means that they are unity if the variables involved are identical up to permissible transformations, and that they can be considered as inner products in a Euclidian space. Some of the coefficients of the correlation family suggested by Janson and Vegelius are generalized squared product-moment correlations and some are not. In the present paper, a family of correlations for variables of mixed scale types is advocated all members of which are generalized squared product-moment correlations. Some practical advantages of the latter family are explained. The authors are obliged to Klaas Nevels and Henk Kiers for helpful comments.     

Using the common-sense model to predict risk perception and disease-related worry in individuals at increased risk for venous thrombosis.

OBJECTIVE: This study applied the Common-Sense Model (CSM) to predict risk perception and disease-related worry in 174 individuals with a genetic predisposition to venous thrombosis (thrombophilia). DESIGN: Participants completed an adapted version of the Illness Perception Questionnaire-Revised (IPQ-R) and measures assessing risk perception and worry. RESULTS: Regression analyses revealed that illness perceptions were predictors of risk perception and thrombosis worry. The hypothesis that illness perceptions mediate the relationship between a person's experience of venous thrombosis and perceived risk and thrombosis worry could not be confirmed. CONCLUSIONS: Further research should refine the IPQ-R for populations at risk of a disease and examine the value of the CSM in explaining the relationship between risk perception, worry, and health behavior.