Determinants of stable volunteering in Swiss soccer clubs

This study analysed the underlying determinants of soccer club volunteers’ tendency to continue or terminate their voluntary engagement. Stable voluntary engagement was analysed in terms of volunteers’ subjective expectations regarding club-related working conditions, expressed by level of job satisfaction and orientation of collective solidarity to their soccer club. These relationships were tested empirically using an online questionnaire with 345 volunteers in a selection of 20 Swiss soccer clubs. The results indicate that the volunteers’ job satisfaction and orientation toward collective solidarity correlated positively with their volunteering commitment. The discussion presents recommendations to help both Swiss soccer clubs as well as the Swiss Soccer Association to retain their volunteers more effectively.     

Improved Estimation of Maximal Reliability for Unidimensional Multicomponent Measuring Instruments in Repeated Measure Studies

In repeated measure studies with unidimensional scales, measurement invariance, and specificity stability over time, the specificity variance in each instrument component can be identified. This article describes for that setting an improved point and interval estimation procedure for the maximal reliability coefficient associated with a given set of homogeneous measures. The method is developed within the framework of latent variable modeling and can also be readily used in longitudinal studies for improved point and interval estimation of individual measure reliability and scale reliability at each assessment occasion. The procedure is based on empirically testable conditions and is illustrated with an example.     

Investigation of reinforcement of the modified carbon black from wasted tires by nuclear magnetic resonance

INTRODUCTION Waste tires cannot degrade in the short term; they may cause accidental fire and emit poisonous gases rich in dioxins. How to recycle and utilize them effectively, and prevent secondary pollution to the environment has become a new issue that the reuse of resources is faced with. Pyrolysis is an environ-ment-friendly process for recycling of used tires. Three products are typically obtained from the pyrolysis of waste tires: gas, oil and char (Gonzalez etal., 2001). Pyrolyt…     

Using centrality of concept maps as a measure of problem space states in computer-supported collaborative problem solving

Problem solving likely involves at least two broad stages, problem space representation and then problem solution (Newell and Simon, Human problem solving, 1972). The metric centrality that Freeman (Social Networks 1:215–239, 1978) implemented in social network analysis is offered here as a potential measure of both. This development research study applied centrality measures to reanalyze existing concept maps from a recent investigation (Engelmann and Hesse, Computer-Supported Collaborative Learning 5:299–319, 2010). Participants (N = 120) were randomly assigned to interdependent (i.e. hidden profiles) or non-interdependent conditions to work online in triads using CmapTools software to create a concept map in order to solve a problem scenario. The centrality values of these group-created concept maps agreed with the common relations count analysis used in that investigation and allowed for additional comparisons as well as analysis by multidimensional scaling. Specifically, the interdependent triad maps resembled the fully explicated problem space, while the non-interdependent triad maps mainly resembled the problem solution. The results demonstrate that centrality is a useful measure of knowledge structure contained in these team concept map artifacts that allows researchers to infer problem representation start and goal state transitions during problem solving.     

Evoking Knowledge and Information Awareness for Enhancing Computer-Supported Collaborative Problem Solving

Computer-supported collaboration by spatially distributed group members still involves interaction problems within the group. This article presents an empirical study investigating the question of whether computer-supported collaborative problem solving by spatially distributed group members can be fostered by evoking knowledge and information awareness, i.e., awareness of a group member with regard to both their fellow collaborators’ domain knowledge and information underlying this knowledge. The study (N = 30 triads) confirmed the efficiency of this approach by comparing (a) an experimental condition in which an environment for fostering knowledge and information awareness was provided and (b) a control condition without such an environment, with regard to communication and cooperation aspects, the quality of the group maps (needed for solving the problems), and the problem-solving performance.     

Can you earn a Ph.D. in economics in five years?

We investigate graduate school outcomes for students who entered economics Ph.D. programs in fall 2002. Students in Top-15 ranked programs and those with higher verbal and quantitative GRE scores are less likely to have dropped out, but no more likely to have graduated. Those with undergraduate degrees from Top-60 U.S. liberal arts colleges and from foreign universities have lower attrition and higher completion probabilities. There are important differences in the characteristics associated with retention and completion probabilities between U.S. citizens and non-citizens and between men and women.