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951.
Javelin throwing is technically demanding. Sequences of upper and lower extremity motions are important for javelin throwing performance. The purpose of this study was to determine the general sequences of upper and lower extremity motions of elite male and female javelin throwers. Three-dimensional kinematic data were collected for 32 female and 30 male elite javelin throwers during competitions. Shoulder, elbow, wrist, hip, knee, ankle, lower trunk, and upper trunk joint and segment angles were reduced for the best trial of each participant. Beginning times of 6 upper extremity and 10 lower extremity joint and segment angular motions were identified. Sequences of the upper and lower extremity motions were determined through statistical analyses. Upper and lower extremity motions of the male and female elite javelin throwers followed specific sequences (P?≤?0.050). Upper extremity motions of the male and female elite javelin throwers did not follow a proximal-to-distal sequence as suggested in the literature. Male and female elite javelin throwers apparently employed different sequences for upper and lower extremity motions (P?0.001). Further studies are needed to determine the effects of sequences of upper and lower extremity motions on javelin throwing performance. 相似文献
952.
Kim Sterelny John Forge Ivan Crozier Sverre Myhra Randall Albury Steve Clarke Yvonne Luxford David Philip Miller Lynn K. Nyhart Mary Chan Richard McDonough Peter J. Riggs Allan Franklin Robert Nola David Bloor Mark Cortiula Thomas Nickles David Oldroyd Nicolas Rasmussen John Forge William A. S. Sarjeant 《Metascience》1998,7(2):331-418
953.
Research in Science Education - Science and science education are recognised internationally as essential for ensuring a sustainable and prosperous future. At the same time, significant equity... 相似文献
954.
Dowe David L.; Gardner Steve; Oppy Graham 《The British journal for the philosophy of science》2007,58(4):709-754
The advent of formal definitions of the simplicity of a theoryhas important implications for model selection. But what isthe best way to define simplicity? Forster and Sober ([1994])advocate the use of Akaike's Information Criterion (AIC), anon-Bayesian formalisation of the notion of simplicity. Thisforms an important part of their wider attack on Bayesianismin the philosophy of science. We defend a Bayesian alternative:the simplicity of a theory is to be characterised in terms ofWallace's Minimum Message Length (MML). We show that AIC isinadequate for many statistical problems where MML performswell. Whereas MML is always defined, AIC can be undefined. WhereasMML is not known ever to be statistically inconsistent, AICcan be. Even when defined and consistent, AIC performs worsethan MML on small sample sizes. MML is statistically invariantunder 1-to-1 re-parametrisation, thus avoiding a common criticismof Bayesian approaches. We also show that MML provides answersto many of Forster's objections to Bayesianism. Hence an importantpart of the attack on Bayesianism fails.
- Introduction
- TheCurve Fitting Problem
- 2.1 Curves and families of curves
- 2.2 Noise
- 2.3 Themethod of Maximum Likelihood
- 2.4 ML and over-fitting
- 2.2 Noise
- 2.1 Curves and families of curves
- Akaike's Information Criterion(AIC)
- The Predictive Accuracy Framework
- The Minimum MessageLength (MML) Principle
- 5.1 The Strict MML estimator
- 5.2 Anexample: Thebinomial distribution
- 5.3 Properties ofthe SMML estimator
- 5.3.1 Bayesianism
- 5.3.2 Languageinvariance
- 5.3.3Generality
- 5.3.4 Consistencyand efficiency
- 5.3.2 Languageinvariance
- 5.4 Similarity to false oracles
- 5.5 Approximationsto SMML
- 5.2 Anexample: Thebinomial distribution
- 5.1 The Strict MML estimator
- Criticisms of AIC
- 6.1 Problems with ML
- 6.1.1 Smallsample biasin a Gaussian distribution
- 6.1.2 Thevon Misescircular and von Mises—Fisherspherical distributions
- 6.1.3 The Neyman–Scottproblem
- 6.1.4 Neyman–Scott,predictive accuracyandminimum expected KL distance
- 6.1.2 Thevon Misescircular and von Mises—Fisherspherical distributions
- 6.2 Otherproblems with AIC
- 6.2.1 Univariate polynomial regression
- 6.2.2 Autoregressiveeconometric time series
- 6.2.3 Multivariatesecond-orderpolynomial modelselection
- 6.2.4 Gapor no gap:a clustering-like problem forAIC
- 6.2.2 Autoregressiveeconometric time series
- 6.3 Conclusionsfrom the comparison of MML and AIC
- 6.1.1 Smallsample biasin a Gaussian distribution
- 6.1 Problems with ML
- Meeting Forster's objectionsto Bayesianism
- 7.1 The sub-family problem
- 7.2 Theproblem of approximation,or, which framework forstatistics?
- 7.1 The sub-family problem
- Conclusion
- Details of the derivation of the Strict MMLestimator
- MML, AIC and the Gap vs. No Gap Problem
- B.1 Expectedsize of the largest gap
- B.2 Performanceof AIC on thegap vs. no gap problem
- B.3 Performanceof MML in thegap vs. no gap problem
- B.2 Performanceof AIC on thegap vs. no gap problem
- B.1 Expectedsize of the largest gap
955.
The effectiveness of online instructional videos in the acquisition and demonstration of cognitive,affective and psychomotor rehabilitation skills 下载免费PDF全文
Darren Cooper Steve Higgins 《British journal of educational technology : journal of the Council for Educational Technology》2015,46(4):768-779
The use of instructional videos to teach clinical skills is an ever growing area of e‐learning based upon observational learning that is cited as one of the most basic yet powerful learning strategies. The aim of the current study is to evaluate the effectiveness of online instructional videos for the acquisition and demonstration of cognitive, affective and psychomotor skills among undergraduate students, throughout formative assessments with two different durations of instructional videos. The research suggests that the use of videos to support traditional learning should be encouraged. While a conclusive evidence—base for their usage has not yet been established they are a medium which is likely to benefit a proportion of a cohort, and it is very unlikely that they will be harmful to students' learning. 相似文献
956.
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958.
In America the ethic of individual achievement has always been balanced by complementary norms of group action. Blacks, however, have been handicapped by a lack of the in-group loyalty required for a united struggle against racial oppression. Black power ideology was conceived as a sociotherapy to increase the level of black group cohesion. This study was designed to provide much needed data on the success of the “therapy.” A survey of 611 black high school students and 93 black college students yielded little evidence that verbally professed endorsement of black power ideology was translated into action. In an experiment. 323 black high school students manifested a consistent tendency to be less helpful to scientists identified as black than to unidentified scientists, regardless of the students' claimed level of black power orientation. 相似文献
959.
960.
Connor S 《New scientist (1971)》1983,100(1385):559