The Accuracy and Consistency of a Series of IRT True Score Equatings

This study investigates a sequence of item response theory (IRT) true score equatings based on various scale transformation approaches and evaluates equating accuracy and consistency over time. The results show that the biases and sample variances for the IRT true score equating (both direct and indirect) are quite small (except for the mean/sigma method). The biases and sample variances for the equating functions based on the characteristic curve methods and concurrent calibrations for adjacent forms are smaller than the biases and variances for the equating functions based on the moment methods. In addition, the IRT true score equating is also compared to the chained equipercentile equating, and we observe that the sample variances for the chained equipercentile equating are much smaller than the variances for the IRT true score equating with an exception at the low scores.     

Statistical Models and Inference for the True Equating Transformation in the Context of Local Equating

Based on Lord's criterion of equity of equating, van der Linden (this issue) revisits the so‐called local equating method and offers alternative as well as new thoughts on several topics including the types of transformations, symmetry, reliability, and population invariance appropriate for equating. A remarkable aspect is to define equating as a standard statistical inference problem in which the true equating transformation is the parameter of interest that has to be estimated and assessed as any standard evaluation of an estimator of an unknown parameter in statistics. We believe that putting equating methods in a general statistical model framework would be an interesting and useful next step in the area. van der Linden's conceptual article on equating is certainly an important contribution to this task.     

Mapping public support for innovation: A comparison of policy alignment in the UK and France

This paper proposes and tests a three-dimensional model of public support design as a framework to compare public incentives for innovation in firms through time and across countries, and consequently to compare forms of policy alignment of innovation objectives in an economy. Using data on 149 French and British policy programmes from the early 1980s to 2002, this paper shows that policy-makers implement programmes within a different three-dimensional design space in order to align several distinctive objectives and consequently strengthen the impact of governmental measures. Moreover, as the objectives of the national players and policy-makers evolved, the portfolio of innovation policies also evolved in their separate ways. Nevertheless, some similar trends are also observed.     

Phase analysis in maximal sprinting: an investigation of step-to-step technical changes between the initial acceleration,transition and maximal velocity phases

Abstract

The aim of this study was to investigate spatiotemporal and kinematic changes between the initial acceleration, transition and maximum velocity phases of a sprint. Sagittal plane kinematics from five experienced sprinters performing 50-m maximal sprints were collected using six HD-video cameras. Following manual digitising, spatiotemporal and kinematic variables at touchdown and toe-off were calculated. The start and end of the transition phase were identified using the step-to-step changes in centre of mass height and segment angles. Mean step-to-step changes of spatiotemporal and kinematic variables during each phase were calculated. Firstly, the study showed that if sufficient trials are available, step-to-step changes in shank and trunk angles might provide an appropriate measure to detect sprint phases in applied settings. However, given that changes in centre of mass height represent a more holistic measure, this was used to sub-divide the sprints into separate phases. Secondly, during the initial acceleration phase large step-to-step changes in touchdown kinematics were observed compared to the transition phase. At toe-off, step-to-step kinematic changes were consistent across the initial acceleration and transition phases before plateauing during the maximal velocity phase. These results provide coaches and practitioners with valuable insights into key differences between phases in maximal sprinting.     

FACILITATING THE DEVELOPMENT OF TALENTS

World class pioneering achievements are a nation's most valuable asset. They arise from the efforts of talents‐people of extraordinary ability. The vital task of fostering the emergence of such talents requires a concentrated effort covering the entire lifespan. Significant factors are parents, contemporaries and teachers as well as media, the societal atmosphere and contact with great social and scientific issues. These must act together to produce talents with not only the ability but also the dedication to achieve.

     

Living while being alive: education and learning in the Treatment Action Campaign

This paper is based on research into the Treatment Action Campaign (TAC) in South Africa. The research investigated whether, through being active members of this social movement, HIV‐positive activists learn things they could not otherwise learn about their status and the epidemic, and how they put such knowledge to use. We show how activists develop a critical understanding of the underlying causes of their ill health and its link to economic poverty and global politics. The paper concludes by suggesting that adult educators can assume direct responsibility for poverty reduction by working in and with social movements.