The kinematic differences between accurate and inaccurate squash forehand drives for athletes of different skill levels     

Benjamin K. Williams  Ross H. Sanders  Joong Hyun Ryu  Philip Graham-Smith  Peter J. Sinclair 《Journal of sports sciences》2020,38(10):1115-1123

ABSTRACT

To maintain the accuracy of squash shots under varying conditions, such as the oncoming ball’s velocity and trajectory, players must adjust their technique. Although differences in technique between skilled and less-skilled players have been studied, it is not yet understood how players vary their technique in a functional manner to maintain accuracy under varying conditions. This study compared 3-dimensional joint and racket kinematics and their variability between accurate and inaccurate squash forehand drives of 9 highly skilled and 9 less-skilled male athletes. During inaccurate shots, less-skilled players hit the ball with a more open racket, demonstrating a difference in this task-relevant parameter. No joint kinematic differences were found for accuracy for either group. Coordinated joint rotations at the elbow and wrist both displayed a “zeroing-in” effect, whereby movement variability was reduced from the initiation of propulsive joint rotation to a higher consistency at ball-impact; potentially highlighting the “functionality” of the variability prior to the impact that enabled consistent task-relevant parameters (racket orientation and velocity) under varying conditions. Further, highly skilled players demonstrated greater consistency of task-relevant parameters at impact than less-skilled players. These findings highlight the superior ability of highly skilled players to adjust their technique to achieve consistent task-relevant parameters and a successful shot.  相似文献   

Static and dynamic accuracy of a magnetic-inertial measurement unit used to provide racket swing kinematics     

Benjamin Kane Williams  Ross H. Sanders  Joong Hyun Ryu  Pitre C. Bourdon  Philip Graham-Smith  Peter J. Sinclair 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(2):202-214

Magnetic-inertial measurement units (MIMUs) are becoming more prevalent in sports biomechanics and may be a viable tool to evaluate kinematic parameters. This study examined the accuracy of a MIMU to estimate orientation angles under static conditions and dynamically from a squash racket during a forehand drive shot. A MIMU was mounted onto a goniometer and moved through 0–90°, with static data collected at 10° increments during 10 repetitions of all three axes. Typical error analyses showed the MIMU to be very reliable (TE ≤ 0.03°). MIMU accuracy was determined via intraclass correlation coefficients (ICC) (r > 0.999, p < 0.001). An ordinary least products regression showed no proportional bias and minimal fixed bias for all axes. Dynamic accuracy was assessed by comparing MIMU and optical motion capture data of squash racket swing kinematics. A MIMU was fixed onto a racket and 10 participants each hit 10 forehand shots. Mean orientation angle error at ball impact was <0.50° and ICC showed very high correlations (r ≥ 0.988, p < 0.001) for all orientations. Swing phase root mean squared errors were ≤2.20°. These results indicate that a MIMU could be used to accurately and reliably estimate selected racket swing kinematics.  相似文献   

Bayesian reasoning in avalanche terrain: a theoretical investigation     

Philip A. Ebert 《Journal of Adventure Education & Outdoor Learning》2019,19(1):84-95

In this article, I explore a Bayesian approach to avalanche decision-making. I motivate this perspective by highlighting a version of the base-rate fallacy and show that a similar pattern applies to decision-making in avalanche-terrain. I then draw out three theoretical lessons from adopting a Bayesian approach and discuss these lessons critically. Lastly, I highlight a number of challenges for avalanche educators when incorporating the Bayesian perspective in their curriculum.  相似文献   

Whose curriculum is it anyway? Stakeholder salience in the context of Degree Apprenticeships          下载免费PDF全文

Philip Powell  Anita Walsh 《Higher Education Quarterly》2018,72(2):90-106

A Degree Apprenticeship model has recently been introduced into the United Kingdom (UK) Higher Education system as part of wider changes to vocational training. The system has experienced numerous rapid changes in regulation and funding, and it is now little understood by many stakeholders. Distinguishing different phases in UK Higher Education, and using a salience model as a lens for analysis, this article identifies and examines stakeholders with regards to their influence on the Higher Education curriculum. The new Degree Apprenticeship model is funded by an employer payroll levy and it requires Higher Education institutions to deliver training to specific standards. This research explores the implications of the model for the Higher Education curriculum, concluding that the direct involvement of employers in the design and delivery of vocational Higher Education introduces untried elements into UK Higher Education on the assumption that the funding requirement will lead to a change in employer behaviour. This, coupled with the opening of Higher Education provision to private providers, transfers power over the curriculum to those with potentially no commitment to wider public values, and may offer a threat to the international standing of UK Higher Education. This article contributes to research in understanding how Higher Education systems respond to, and actors cope with, imposed change.  相似文献   

The Program for Cooperative Cataloging’s Transformative Role as a Leader of Change     

Philip E. Schreur 《Cataloging & classification quarterly》2020,58(3-4):397-402

Abstract

The transformation of library metadata encoded in MARC to linked data will enable libraries to participate in the Semantic Web. This transformation, however, will be an iterative development dependent upon community-based decisions. The PCC, as a community-based organization, is ideally positioned to lead this transformation. As PCC guides this transition, three broad areas must be resolved: the conversion of legacy data to linked data, the use of identifiers to support controlled headings, and the transformation of current workflows to linked-data counterparts. By embracing the Web as a community, PCC can confirm its relevance in a complex web of global data.  相似文献   

Mapping continuity and change in the intellectual structure of the knowledge base on problem-based learning, 1974–2019: A systematic review     

Philip Hallinger 《British Educational Research Journal》2020,46(6):1423-1444

Problem-based learning (PBL) emerged during the 1970s in response to demands for active learning methods capable of developing transferable knowledge and skills in the training of doctors. Over succeeding decades, PBL was gradually adopted in other fields of education. This systematic review aimed to identify key streams of theory and empirical research that have emerged over time in PBL research and practice. The review sourced 12,036 Scopus-indexed documents published between 1974 and 2019. Science mapping was used to reveal the ‘intellectual structure’ or key research themes that have evolved in this literature over the past 45 years. The science mapping tool used in this review was author co-citation analysis conducted in VOSviewer software. Author co-citation analysis identified three schools of thought that together describe the intellectual structure of the PBL knowledge base: Design of PBL Curriculum and Instruction; PBL Effectiveness; Theory and Practice in Active Learning. In addition to portraying the intellectual structure of the literature as a whole, the review also conducted longitudinal analyses aimed at highlighting structural changes in this field over time. These analyses found that although the size and impact of schools of thought associated with Design of PBL Curriculum and Instruction and PBL Effectiveness increased over time, they remained stable in terms of theoretical foci. However, the Active Learning school evolved from a small school of authors associated with Cognitive Learning Theories prior to 2000 into the largest school of thought during the most recent decades. These findings both reaffirm the theoretical underpinnings of the PBL knowledge base and highlight its increasing integration with other forms of active learning.  相似文献   

Alternative constructs and cognitive development: Commonalities,divergences, and possibilities for evidence     

Dr. Philip Adey 《Research in Science Education》1992,22(1):1-10

The last fifteen years of research in science education has seen the emergence, flowering, proliferation, and now perhaps slight wilting of studies of pupils' alternative constructs. Meanwhile the older, broadly Piagetian, tradition of work rooted in notions of cognitive development was attacked as being, inter alia, deterministic, concentrating on what children could not do, and getting even that wrong since children could be shown to be a lot cleverer than the cognitive developmentalists claimed. The time has perhaps now come to look at these two lines of work together to see what assumptions they share and where their paradigms, aims, and methods differ significantly. In this paper I will claim that there is far less antagonism between the two traditions than is often represented, but that nevertheless the differences are fundamental and lead to different views of the purposes and potential of science education. Possible evidence that might be adduced in support of one view at the expense of the other will be considered and exemplified with recent results of a cognitive acceleration project. Specializations: cognitive development, curriculum development, in-service education, project evaluation.  相似文献   

Resilience in College Students     

Philip Rosenbaum  Ryan D. Weatherford 《Journal of College Student Psychotherapy》2017,31(2):91-92

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Predicting Academic Success: A Longitudinal Study of University Design Students     

Philip Crowther  Sarah Briant 《The International Journal of Art & Design Education》2021,40(1):20-34

This article presents a longitudinal study, over eleven years, of the academic progress of a cohort of design students (n = 475) at a major Australian university. The students were from four different spatial design disciplines: architecture, industrial design, interior design, and landscape architecture. The article identifies cognitive variables that may predict future academic success. This research uses regression analysis to identify correlations across a range of variables, in particular exploring the relationship between university entrance scores, subjects studied at school (art and graphics) and academic success as defined by university grade point average and time to completion. This study shows that prior knowledge in art and graphics is not a useful predictor of future academic success, while university entrance scores and first year performance are related to ongoing academic success. These results suggest that for the design disciplines explored here, discipline‐specific prior knowledge is not an important requirement for university entrance.  相似文献   

Supporting the intellectual life of a democratic society     

Philip E. Agre 《Ethics and Information Technology》2001,3(4):289-298

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