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971.
Tuan Dinh Nguyen Marisa Cannata Jason Miller 《The Journal of educational research》2018,111(2):163-174
Recent theoretical conceptualizations of student engagement have raised questions about how to measure student engagement and how engagement varies not only across schools, but also within school and within classrooms. The authors build on existing research on student behavioral engagement and extend this research to emphasize a continuum of disengagement, active engagement, and passive engagement. They review common approaches to measuring engagement and highlight areas where new theoretical conceptualizations of engagement require new approaches to measurement. The authors analyze how student behavioral engagement changed depending on the context and demonstrate the need of a finer scale of engagement. They find there was not a uniform association of higher behavioral engagement and student interaction with peers, but it was the interaction with other students and the teacher that was predictive of increased engagement. Their work suggests that disaggregating behavioral engagement into disengagement, active engagement, and passive engagement has important research and conceptual implications. 相似文献
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The aim of this study was to determine the effects of external loading on power output during a squat jump on a force platform in athletes specializing in strength and power events (6 elite weight-lifters and 16 volleyball players) and in 20 sedentary individuals. Instantaneous power was computed from time-force curves during vertical jumps with and without an external load (0, 5 or 10 kg worn in a special vest). The jumps were performed from a squat position, without lower limb counter-movement or an arm swing. Peak instantaneous power corresponded to the highest value of instantaneous power during jumping. Average power throughout the push phase of the jump was also calculated. A two-way analysis of variance showed significant interactions between the load and group effects for peak instantaneous power (P< 0.01) and average power (P< 0.001). Peak instantaneous power decreased significantly in sedentary individuals when moderate external loads were added. The peak instantaneous power at 0 kg was greater than that at 5 and 10 kg in the sedentary individuals. In contrast, peak instantaneous power was independent of load in the strength and power athletes. Mean power at 0 kg was significantly lower than at 5 kg in the athletes; at 0 kg it was significantly higher than at 10 kg in the sedentary males and at 5 and 10 kg in the sedentary females. In all groups, the force corresponding to peak instantaneous power increased and the velocity corresponding to peak instantaneous power decreased with external loading. The present results suggest that the effects of external loading on peak instantaneous power are not significant in strength and power athletes provided that the loads do not prevent peak velocity from being higher than the velocity that is optimal for maximal power output. 相似文献
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Instructions for Authors
Instructions for Authors 相似文献980.
Attempts to increase dive height by introducing a period of flight in the final approach step preceding the hurdle of dives from forward and reverse groups were investigated. One study involved 11 collegiate-level divers experienced in both traditional and hurdle preflight techniques. In a second study, dives executed by 9 national-level women were compared. Dives with a hurdle preflight had shorter final approach steps and greater hurdle flight durations. Flight time differences in favor of hurdle preflight techniques diminished from final approach step through hurdle flight to dive flight. Although the collegiate-level divers had longer dive flight times when using a hurdle preflight, it was suggested that the costs of these techniques may outweigh their potential benefits. 相似文献