Relationships among field-test measures and physical match performance in elite-standard soccer referees     

Matthew Weston  Carlo Castagna  Werner Helsen  Franco Impellizzeri 《Journal of sports sciences》2013,31(11):1177-1184

Abstract

The aim of this study was to assess the extent to which measures derived from the new FIFA referees’ fitness tests can be used to monitor a referee's match-related physical capacity. Match-analysis data were collected (Prozone®, Leeds, UK) from 17 soccer referees for 5.0 (s = 1.7) FA Premier League matches per referee during the first 4 months of the 2007–08 season. Physical match performance categories included total distance covered, high-intensity running distance (speed >5.5 m · s^?1), and sprinting distance (>7.0 m · s^?1). The two tests were a 6 × 40-m sprint test and a 150-m interval test. Heart rate demand was correlated with total match distance covered (r = ?0.70, P = 0.002) and high-intensity running (r = ?0.57, P = 0.018) in the interval test. The fastest 40-m sprint was related to total distance covered (r = ?0.69, P = 0.002), high-intensity running (r = ?0.76, P < 0.001), and sprinting distance (r = ?0.75, P = 0.001), while mean time for the 40-m sprints was related to total distance covered (r = ?0.70, P = 0.002), high-intensity running (r = ?0.77, P < 0.001), and sprinting distance (r = ?0.77, P < 0.001). The referees who recorded the best interval-test heart rate demand and fastest 40-m time produced the best physical match performances. However, only the sprint test and in particular the fastest 40-m time had appropriate construct validity for the physical assessment of soccer referees.  相似文献   

Teaching methods for modelling problems and students’ task-specific enjoyment, value, interest and self-efficacy expectations     

Stanislaw Schukajlow  Dominik Leiss  Reinhard Pekrun  Werner Blum  Marcel Müller  Rudolf Messner 《Educational Studies in Mathematics》2012,79(2):215-237

In this study which was part of the DISUM-project, 224 ninth graders from 14 German classes from middle track schools (Realschule) were asked about their enjoyment, interest, value and self-efficacy expectations concerning three types of mathematical problems: intra-mathematical problems, word problems and modelling problems. Enjoyment, interest, value and self-efficacy were assessed before and after a ten-lesson teaching unit promoting modelling competency related to the topics “Pythagoras’ theorem” and “linear functions”. The study aimed to answer the following research questions: (1) Do students’ enjoyment, value, interest and self-efficacy expectations differ depending on the type of task? (2) Does the treatment of modelling problems in classroom instruction influence these variables? (3) Are there any differential effects for different ways of teaching modelling problems, including a “directive”, teacher-centred instruction and an “operative-strategic”, more student-centred instruction emphasising group work and strategic scaffolding by the teacher? The findings show that there were no differences in students’ enjoyment, interest, value and self-efficacy between the three types of tasks. However, teaching oriented towards modelling problems had positive effects on some of the student variables, with the student-centred teaching method producing the most beneficial effects.  相似文献   

MAINTAINING,REFRAMING, AND DISRUPTING TRADITIONAL EXPECTATIONS AND OUTCOMES FOR PROFESSIONAL DEVELOPMENT WITH CRITICAL FRIENDS GROUPS     

Wendy Burke  Gary E. Marx  James E. Berry 《The Teacher Educator》2013,48(1):32-52

Districts across the country are currently adopting models of professional learning communities (PLCs) as a means for improving teachers' instructional practice and student achievement. This evaluation research case study shares the 3-year history, development, and challenges of a district-wide implementation of Critical Friends Groups (CFGs), a particular format for PLCs. Using Argyris and Schön's (1974) theories of action framework, the authors identify teachers' espoused theories about a contextually situated CFG initiative and examine teachers' conceptualizations about the ways in which their work influences the progression and effectiveness of this professional development model. Findings from this study suggest that the degree to which the CFG implementation model is integrated with other school improvement initiatives, specifically those that address teachers' professional development, dramatically influences how key stakeholders conceptualize and draw the necessary connections to their roles in improving instructional practice and addressing student achievement and learning.  相似文献   

Student teachers’ pedagogical content knowledge for teaching systems thinking: effects of different interventions     

Frank Rosenkränzer  Christian Hörsch  Stephan Schuler  Werner Riess 《International Journal of Science Education》2013,35(14):1932-1951

ABSTRACT

Systems’ thinking has become increasingly relevant not only in education for sustainable development but also in everyday life. Even if teachers know the dynamics and complexity of living systems in biology and geography, they might not be able to effectively explain it to students. Teachers need an understanding of systems and their behaviour (content knowledge), and they also need to know how systems thinking can be fostered in students (pedagogical content knowledge (PCK)). But the effective development of teachers’ professional knowledge in teaching systems thinking is empirically uncertain. From a larger study (SysThema) that investigated teaching systems thinking, this article reports the effects of the three different interventions (technical course, didactic course and mixed course) in student teachers’ PCK for teaching systems thinking. The results show that student teachers’ PCK for teaching systems thinking can be promoted in teacher education. The conclusion to be drawn from our findings is that a technically orientated course without didactical aspects seems to be less effective in fostering student teachers’ PCK for teaching systems thinking. The results inform educators in enhancing curricula of future academic track and non-academic track teacher education.  相似文献   

Knowledge management supporting education and research at a university cleanroom     

Linda?NowackEmail author  Thomas?Maul  Werner?Kraus  Walter?Hansch 《知识管理研究与实践》2009,7(1):100-112

At the university, each institute or chair can be seen as a small independent enterprise in respect of education and research. For this reason, the efficiency of management as well as the improvement of education and research within this unit is more and more at a premium. The students need a good working environment and the opportunity to gain and share information in order to carry out successful research and course work. This paper shows how education at a university semiconductor laboratory can be improved by using a content management system to build a knowledge management system. The structuring and implementation will be shown as well as students’ rating of it. The results support the conclusion that the knowledge base is a great step forward for improving education and research in a complex environment.  相似文献   

On the constitution and configuration of higher-order compounds     

Alfred Werner  Marshall McLuhan 《Resonance》1999,4(9):90-94

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Muskuläre Regulation bei ermüdungsinduzierter Vorbelastung im Krafttraining     

Prof. Dr. Hans-Alexander Thorhauer  Sven Michel  Norman Stutzig  Lutz Hoffmann  Falk Werner 《Sportwissenschaft》2010,40(3):182-190

International sport strives for increasing the level of performance in sports. Risks of manipulating the performance are not unusual. At the same time, improvements in science, engineering and data processing offer further opportunities for planning effective, low-risk and year-round training programmes for specific sports. This paper presents new approaches based on the example of techniques for strength training. Selected experimental results highlight the limitations and provide conclusions for the scientific foundation and individualization of high performance training. The approach of “muscle pre-fatigue” is verified in a training study with high jumpers. The statements show how important scientifically controlled analysis is for individual training programmes and what high significance they have for optimizing the training process. These will be essential requirements for a legal improvement of high performance in international sport.  相似文献   

Training of perceptual-cognitive skills in offside decision making   总被引：1，自引：0，他引：1  

Catteeuw P  Gilis B  Jaspers A  Wagemans J  Helsen W 《运动与训练心理学杂志》2010,32(6):845-861

This study investigates the effect of two off-field training formats to improve offside decision making. One group trained with video simulations and another with computer animations. Feedback after every offside situation allowed assistant referees to compensate for the consequences of the flash-lag effect and to improve their decision-making accuracy. First, response accuracy improved and flag errors decreased for both training groups implying that training interventions with feedback taught assistant referees to better deal with the flash-lag effect. Second, the results demonstrated no effect of format, although assistant referees rated video simulations higher for fidelity than computer animations. This implies that a cognitive correction to a perceptual effect can be learned also when the format does not correspond closely with the original perceptual situation. Off-field offside decision-making training should be considered as part of training because it is a considerable help to gain more experience and to improve overall decision-making performance.  相似文献   

Errors in judging "offside" in association football: test of the optical error versus the perceptual flash-lag hypothesis     

Helsen W  Gilis B  Weston M 《Journal of sports sciences》2006,24(5):521-528

The objective of this study was to analyse the correctness of the offside judgements of the assistant referees during the final round of the FIFA 2002 World Cup. We also contrasted two hypotheses to explain the errors in judging offside. The optical error hypothesis is based on an incorrect viewing angle, while the flash-lag hypothesis refers to perceptual errors associated with the flash-lag effect (i.e. a moving object is perceived as spatially leading its real position at a discrete instant signalled by a briefly flashed stimulus). Across all 64 matches, 337 offsides were analysed using digital video technology. The error percentage was 26.2%. During the first 15 min match period, there were significantly more errors (38.5%) than during any other 15 min interval. As predicted by the flash-lag effect, we observed many more flag errors (86.6%) than non-flag errors (13.4%). Unlike the predictions of the optical error hypothesis, there was no significant difference between the correct and incorrect decisions in terms of the positioning of the assistant referees relative to the offside line (0.81 and 0.77 m ahead, respectively). To reduce the typical errors in judging offside, alternative ways need to be considered to teach assistant referees to better deal with flash-lag effects.  相似文献   

Activity profile of top-class association football referees in relation to fitness-test performance and match standard   总被引：1，自引：1，他引：0  

Mallo J  Navarro E  Aranda JM  Helsen WF 《Journal of sports sciences》2009,27(1):9-17

The aim of this study was to examine the kinematic activity profiles, cardiovascular responses and physical fitness of top-class football referees (n=11) during the FIFA Confederations Cup 2005. Computerised match-analyses (n=9) were performed with a two-dimensional photogrammetric video system, and the cardiovascular demand imposed on the referees (n=12) was measured using heart rate recordings. Total distance covered was 10,218, s=643 m of which 3531, s=510 m was covered at high intensities (>3.6 m.s(-1)). Both total distance covered (r2=0.59; P=0.02) and high-intensity activities (r2=0.44; P=0.05) were related to the distance covered by the ball in the same match. The referees ran at high speed 37% further (P=0.01) in the actual tournament than during under-17 top-level officiating. After the 5-min interval during which high-speed running peaked, in the following 5 min the performance was reduced by 19% (P=0.01) in relation to the mean of the game. Mean heart rate was 161, s=9 b.min(-1) (86, s=3% of maximal heart rate (HRmax)). Mean heart rate (expressed as percentage of HRmax) was related in part (r2=0.36; P<0.01) to the number of high-intensity activities performed in the same 5-min interval. The results of this study show that: (1) kinematic activity profiles of top-class referees can be influenced by the distance covered by the ball; (2) the amount of high-speed running (>5 m.s(-1)) best describes the physical performance of referees; (3) heart rate recording can be a useful tool to determine the most intense periods of a match and (4) the new fitness tests adopted by FIFA were poor predictors of match activities.  相似文献