Investigation of high-speed badminton racket kinematics by motion capture

The kinematics of a badminton racket during a smash stroke was observed in this study with the purpose of investigating stroke dynamics and racket behaviour. Motion capture measurements of the racket during several smash strokes performed by three players of different skill levels indicated a clear increase in racket velocity at impact with increasing skill level. Variations between translational and rotational contributions to the impact speed could also be seen between the players. The advanced player produced a much higher peak angular velocity and also relied much less on translation, with a translational velocity of only 8% of the total velocity versus the 20% for the recreational player. It is proposed that, as an alternative to shuttlecock speeds, racket head speed measurements can be used as an indicator of performance, and can also provide some insight into the interaction between the racket and player.     

An interview study of why parents conduct intensive ABA home training for their child with autism spectrum disorder. An analysis from the lens of the dialectical disability model

The number of parents undertaking an intensive home training programme of children with disabilities (e.g. Applied Behavioural Analysis) has increased. It reveals a paradox in current disability research and policies. On the one hand, policies in general are aimed at inclusion through movement of social barriers for participation, grounded in the social model of disability. On the other hand, intensive home training is based on the aim of rehabilitation through intensive training of individual cognitive and social skills, an approach grounded in a bio-medical model. Intensive home training programmes are supported by political legislation that enables parents to partake the training and hire the necessary helpers. How is this paradox viewed from the perspective of the parents? From the departure of the dialectical model of disability – and its central concepts of developmental incongruence, developmental time and social agency – two mothers practising home training with their children with autism disorder were interviewed about their motives for home training and subsequent experience with their child. Results showed that the motive to home training was to create a local congruence that allowed the child to thrive. Intensive home training also restored the mothers’ sense of agency vis-à-vis their child’s development. However, home training might not abolish the need for adaptations of the child’s social practices outside the family. It is discussed how societal support to home training risks to hinder higher order reorganisation of developmental opportunities that are necessary to actualise policy statements of inclusion.     

Configuring the teacher as data user: public-private sector mediations of national test data

ABSTRACT

Datafication of student learning has carved out an influential space for public and private actors who design technologies for visualizing data. As data visualizations shape how teachers’ interpret data, they are powerful devices. This paper examines how teachers get configured as data users in the making of Danish national test data visualizations for municipal primary and lower secondary schools. The paper is based on a qualitative study of the Danish Ministry of Education, which develops the official visualizations, and NordicMetrics, a private consultancy offering a supplementing visualization of student progression. We draw on science and technology studies (STS) to theorize techno-organizational dynamics of developing visualizations. We propose to understand data visualizations as contingent, situated and socio-material achievements that configure teacher as data users. Comparing two institutions’ respective negotiations of different concerns when developing data visualizations enables us to consider the otherwise ‘hidden’ data mediators and the entwined relations between public and private data mediators.     

Water Quality Statistics

Water quality experiments, especially the use of macroinvertebrates as indicators of water quality, offer an ideal context for connecting statistics and science. In the STAR program for secondary students and teachers, water quality experiments were also used as a context for teaching statistics. In this article, we trace one activity that uses virtual streams and repeated sampling to develop the notion of a hypothesis test for one proportion.     

Implementation of engineering product design using international student teamwork—to comply with future needs

This paper describes a semester concerned with international student teamwork. Here we emphasize the development of technical as well as personal competencies. Participants have completed at least four academic semesters at university or college. Students are given an opportunity to use their acquired knowledge, to develop a deeper insight of technical subjects and integrate them through product development. One hundred and ninety-five students from 14 different countries have joined since the start in 1995. The paper reports our experience of product design implementation in an integrated engineering context. Design is not an isolated activity; it must be integrated with the entire spectrum of activities within the company. The designer must learn to appreciate the requirements of marketing and work within the bounds of available technology. The course teaches that collaboration and co-operation are vital activities of every designer. It is important to ensure that the product designed fulfils the market needs and can be manufactured competitively. A system to assess both individual contribution and group performance is reported. This semester has proved to be an effective way to develop skills needed and to develop students' international awareness alongside their enhanced technical skills. This semester contributes to developing European competitiveness.     

Training science teachers with fully-interactive,distance education technology

Conclusion Our experience with interactive distance education for science teachers has been both exciting and rewarding. This class has convinced us that activity-based science method classes can be presented with this technology. Working with distance education equipment requires the creative combination of long-established teaching techniques with novel procedures required by the technology. Although the technology does involve inevitable limitations and compromises, it sharpens some teaching skills and provides an opportunity for teachers to learn and do more science. As available tools for distance education become even more sophisticated, delivery techniques will have to be altered continually. Doubtlessly, technological developments will continue to be increasingly site friendly. In the future, one can anticipate forms of distance education that will enable communication with an infinite number of remote sites, thus establishing the definitive electronic science classroom.     

The Relationship Between Changes in Teachers' Self-efficacy Beliefs and the Science Teaching Environment of Danish First-Year Elementary Teachers

This study's purpose was to determine whether science teaching self-efficacy beliefs among new teachers of elementary science interact significantly with teaching environments in their schools. The study hypothesized a mechanism by which environments can interact with self-efficacy and, consequently, affect the quality of science teaching. The self-efficacy of new elementary teachers from Denmark was assessed at the beginning, middle, and end of their first year of teaching. Their teaching success and environments were also assessed. It was found that positive changes in self-efficacy seemed positively related to the occurrence of environmental factors helpful to teaching (r= .401; p= .011; n= 39). In three case studies, there was some support for this association from assessments, interviews, and success in teaching.     

Biomechanical differences in soccer kicking with the preferred and the non-preferred leg

The aims of this study were to examine the release speed of the ball in maximal instep kicking with the preferred and the non-preferred leg and to relate ball speed to biomechanical differences observed during the kicking action. Seven skilled soccer players performed maximal speed place kicks with the preferred and the nonpreferred leg; their movements were filmed at 400 Hz. The inter-segmental kinematics and kinetics were derived. A coefficient of restitution between the foot and the ball was calculated and rate of force development in the hip flexors and the knee extensors was measured using a Kin-Com dynamometer. Higher ball speeds were achieved with the preferred leg as a result of the higher foot speed and coefficient of restitution at the time of impact compared with the non-preferred leg. These higher foot speeds were caused by a greater amount of work on the shank originating from the angular velocity of the thigh. No differences were found in muscle moments or rate of force development. We conclude that the difference in maximal ball speed between the preferred and the non-preferred leg is caused by a better inter-segmental motion pattern and a transfer of velocity from the foot to the ball when kicking with the preferred leg.