Situation-orientated recognition of tactical patterns in volleyball

One important factor for effective operations in team sports is the team tactical behaviour. Many suggestions about appropriate players' positions in different attack or defence situations have been made. The aims of this study were to develop a classification of offensive and defensive behaviours and to identify team-specific tactical patterns in international women's volleyball. Both the classification and identification of tactical patterns is done by means of a hierarchical cluster analysis. Clusters are formed on the basis of similarities in the players' positions on the court. Time continuous data of the movements, including the start and end points during a pass from the setter, are analysed. Results show team-specific patterns of defensive moves with assessment rates of up to 80%. Furthermore, the recognition of match situations illustrates a clear classification of attack and defence situations and even within different defence conditions (approximately 100%). Thus, this approach to team tactical analysis yields classifications of selected offensive and defensive strategies as well as an identification of tactical patterns of different national teams in standardized situations. The results lead us to question training concepts that assume a team-independent optimal strategy with respect to the players' positions in team sports.     

Re-disciplining Academic Careers? Interdisciplinary Practice and Career Development in a Swedish Environmental Sciences Research Center

Minerva - Interdisciplinarity is often framed as crucial for addressing the complex problems of contemporary society and for achieving new levels of innovation. But while science policy and...     

Validity of block start performance without arm forces or by kinematics-only methods

The purpose of this study was to validate the calculation of reaction time (RT) and normalised power in block starts without considering arm ground reaction forces (GRFs) or using two kinematics-only methods. The RT and normalised power in the action phase were calculated using four different methods: using GRFs of arms and legs by force plates (whole F-based method), which can be regarded as the most valid method, using GRFs of legs captured by force plates (legs F-based method), using position of the centre of mass of the entire body captured by high-speed cameras (whole P-based method), and using only a partial subset of segment position (partial P-based method). Bland–Altman plots demonstrated that the RT of the legs F-based method was not similar to that of the whole F-based method: the mean difference was 7.4 ms and the 95% limits of agreement was?45.1 to 59.8 ms, and it was the least valid method for the calculation among the four methods. In contrast, the normalised power was more valid in the legs F-based method, followed by whole and partial P-based methods. This information will help researchers and practitioners to decide upon their analysis methods when analysing block start performance.     

混合聚类方法用于科学结构研究——以“心理学、社会学和教育学”领域为例

在前期的相关研究中,一种基于"引文-文本"相似度的混合聚类方法被用来对2002-2006年期间Webof Science数据库中8305种期刊进行了聚类分析,得到22聚类和7聚类两种体系。与之前的宏观分析不同,7聚类体系中的一个特定的聚类,即"心理学、社会学和教育学"聚类,将被集中研究。该聚类的内部学科结构以及其在22聚类体系中如何分解为三个子聚类将被细致地讨论和分析。对聚类之间的互引网络以及聚类中不同类型的"重要期刊"进行了展示,此外,还进一步将该聚类中760种期刊的混合聚类结果与Thomson-Reuters公司的ESI学科分类进行了对比,基于比较分析的结果,对该领域内部的科学结构进行了量化解读。     

Prospective Teachers' Conceptions of the Knowledge Base for Teaching Chemistry at the German Gymnasium

Journal of Science Teacher Education -     

Individual and co-operative learning with interactive animated pictures

Computer-based multimedia learning environments make it possible to present interactive animated pictures, which can be manipulated for active exploratory learning and which allow the dynamic behavior of complex subject matter to be displayed. Due to the large range of possibilities for exploratory interaction, such learning environments seem well suited for co-operative learning in which different learners analyse the presented subject matter from different perspectives. This paper first describes a theoretical framework for learning from texts and pictures together with an analysis of possible effects of animation and interactivity on knowledge acquisition. It then presents two empirical studies in which knowledge acquisition from interactive animated pictures was compared with knowledge acquisition from static pictures under the conditions of individual learning (Study I) and of cooperative learning (Study II). In Study I, learning with interactive animated pictures resulted in a superior encoding of detail information, but did not facilitate performance of mental simulation tasks. In Study II, learning with interactive animated pictures resulted both in inferior encoding of detail information and poorer results in mental simulations. These findings and the analysis of discourse protocols of subjects’ co-operation suggest that exploratory learning with interactive animated pictures is associated with extraneous cognitive load and that this load can be further increased by the co-ordination demands of co-operative learning. Although animated pictures may provide external support for mental simulations, they do not appear to be generally beneficial for learning, because they can prevent individuals from performing relevant cognitive processes.     

Editorial

When founding the International Journal of Public Opinion Research,the editors had a vision that the journal would be both internationaland interdisciplinary, while retaining a broad interest in boththeoretical and empirical scholarly work. We included reviews,first of books and then of articles reporting on work in thefield, and then     

Editorial

This issue of the International Journal of Public Opinion Researchonce again takes the reader on a trip around the world. Fourcontinents are looked at, counting the two Americas separately,and data from 19 individual countries feature in the analyses,which pertain to several dozens more. We begin our trip in LatinAmerica. Rodolfo Sarsfield and Fabián Echegaray presentcomparative research covering eight major countries on the continent.One always expects, in comparative studies, large tables thatpresent results