The purpose of this study was to document how teachers and students describe and comprehend the ways in which participating
in an augmented reality (AR) simulation aids or hinders teaching and learning. Like the multi-user virtual environment (MUVE)
interface that underlies Internet games, AR is a good medium for immersive collaborative simulation, but has different strengths
and limitations than MUVEs. Within a design-based research project, the researchers conducted multiple qualitative case studies
across two middle schools (6th and 7th grade) and one high school (10th grade) in the northeastern United States to document
the affordances and limitations of AR simulations from the student and teacher perspective. The researchers collected data
through formal and informal interviews, direct observations, web site posts, and site documents. Teachers and students reported
that the technology-mediated narrative and the interactive, situated, collaborative problem solving affordances of the AR
simulation were highly engaging, especially among students who had previously presented behavioral and academic challenges
for the teachers. However, while the AR simulation provided potentially transformative added value, it simultaneously presented
unique technological, managerial, and cognitive challenges to teaching and learning. 相似文献
The goalkeeper’s difficulty in the soccer penalty kick originates from the extreme spatiotemporal constraints of the situation. The present review claims that the current understanding is biased toward attributing a goalkeeper’s success in saving a penalty kick to perceptual–cognitive skill. To investigate the goalkeeper’s skill, researchers have often adopted video tasks. In doing so, they studied perceptual skill in isolation from action. We use affordance-based control theory to propose an alternative understanding and research methodology. We argue that goalkeepers in the penalty kick situation should regulate their actions in ways that sustain the perception of stoppability. To capture this, we outline the building blocks for a required lateral velocity model, in which the goalkeepers’ required actions are scaled to their maximum capabilities. In doing so, we provide new directions for research. 相似文献
Game-based training drills are popular in team sports. This study compared two game-based training conditions and official matches in team handball. Thirty-one women players wore inertial measurement units in five training sessions and five official matches. In training, 3vs3 and 6vs6 game-based training conditions were performed with a 5-min duration. PlayerLoad? and high-intensity events (HIEs; >2.5 m · s?1) were extracted from the raw data. Data were analysed using magnitude-based inferences and reported with effect sizes (ESs). PlayerLoad? · min?1 from all positions combined was 11.37 ± 0.49 (mean ± 90% confidence limits) and 9.71 ± 0.3 for the 3vs3 and 6vs6 conditions, respectively. Backs (ES: 1.63), wings (ES: 1.91), and pivots (ES: 1.58) had greater PlayerLoad? in 3vs3 than 6vs6. Substantially greater HIE · min?1 in 3vs3 occurred for all positions. There was substantially greater PlayerLoad? · min?1 in 3vs3 and 6vs6 than match play for backs, wings, and pivots. Wings (ES: 1.95), pivots (ES: 0.70), and goalkeeper (ES: 1.13) had substantially greater HIE · min?1 in 3vs3 than match play. This study shows greater PlayerLoad? and HIE in 3vs3 than 6vs6. Both game-based training conditions investigated in this study provide an overload in overall PlayerLoad?; however, additional exercises might be needed to overload HIE, especially for backs and pivots. 相似文献
This randomised controlled trial investigated changes in eccentric hamstring strength, 10m sprint speed, and change-of-direction (COD) performance immediately post Nordic hamstring curl (NHC) intervention and following a 3-week detraining period.
Fourteen male team sports athletes were randomised to a do-as-usual control group (CG; n = 7) or to a NHC intervention group (NHC; n = 7). Isokinetic dynamometry at 180°/s evaluated eccentric hamstring strength immediately post-intervention as the primary outcome measure. Secondary outcomes included 10 m sprint time and COD. Each outcome was measured, pre, immediately post-intervention and following a 3-week detraining period.
Immediately post-intervention significant group differences were observed in the NHC group for eccentric hamstring strength (31.81 Nm?1 vs. 6.44 Nm?1, P = 0.001), COD (?0.12 s vs. 0.20 s; P = 0.003) and sprint (- 0.06 s vs. 0.05 s; P = 0.024) performance. Performance improvements were maintained following a detraining period for COD (?0.11 s vs. 0.20 s; P = 0.014) and sprint (?0.05 s vs. 0.03 s, P = 0.031) but not eccentric hamstring strength (15.67 Nm?1 vs. 6.44 Nm?1, P = 0.145) These findings have important implications for training programmes designed to reduce hamstring injury incidence, whilst enhancing physical qualities critical to sport. 相似文献
ABSTRACT Ankle injuries are highly prevalent in ballet, with strength highlighted as a primary risk factor. To profile ankle strength, fourteen female ballet dancers (age: 19.29 ± 1.59 years) completed an isokinetic testing protocol comprising concentric eversion (CONEV) and inversion (CONINV), and, eccentric inversion (ECCINV) trials at four angular velocities (30° · s?1, 60° · s?1, 90° · s?1, 120° · s?1) for both the dominant and non-dominant limb. In addition to Peak Torque (PT) and the corresponding Dynamic Control Ratios (DCRs), angle-specific derivatives of strength (AST) and Functional Range (FR) were calculated. There was no evidence of any significant bilateral strength asymmetry (p = 0.90) across all metrics, and no significant interactions with limb and contraction mode or velocity. A significant main effect for contraction mode (p = 0.001) highlighted greater ECCINV strength – which was maintained with increasing isokinetic velocity – in contrast to reductions in CONEV and CONINV strength. Specifically, dancers are ECCINV dominant at angular velocities greater than 60° · s?1, which is likely to be characteristic of most functional tasks. The lack of bilateral asymmetry may be attributed to dance training interventions that facilitate bilateral development, but ipsilateral mode and velocity-specific asymmetries have implications for injury risk and the training needs of female ballet dancers. 相似文献
The effectiveness of multicultural training among a sample of predominately Hispanic counseling students was examined. The results of a series of 2‐factor repeated measures analysis of variance and follow‐up paired‐samples t tests suggest that multicultural training was effective in increasing students' multicultural competencies and in improving their cognitive racial attitudes. Students' affective racial attitudes were not changed. Students' perceptions of their multicultural training suggest that students from diverse racial/ethnic backgrounds may experience multicultural training differently and unique life experiences may help explain this difference. Counselor educators may wish to use a variety of training experiences to provide multicultural training that is effective across diverse student populations. 相似文献
A study assessing the mechanical behaviour of six natural turf pitches of varying sporting level and surface construction was undertaken over a period of 10?months, spanning a sporting season (August 2010 to May 2011). Penetration resistance and shear resistance were measured with the GoingStick?, impact hardness and surface energy absorption were measured with the 2.25?kg Clegg Impact Soil Tester and the Dynamic Surface Tester device, respectively. The two sand rootzone pitches were more resistant to deformation and less variable in their impact behaviour (impact hardness and energy absorption) through the season than the native soil pitches containing greater proportions of silt and clay. Greater consistency was shown for penetration resistance and shear resistance on one of the sand rootzone pitches, with the other behaving similar to the native soil pitches for these parameters. The sand rootzone surfaces exhibited greater (P?<?0.05) impact hardness than the native soil pitches in the winter period of the season (November to mid-March) compared to the beginning or end periods of the season, where data were statistically similar (P?>?0.05). The greater consistency of sand rootzone surfaces should be considered for the effect it may have on player and team performance, and injury potential. Analysis of data against Performance Quality Standard benchmarks indicated that all data on the sand rootzones exceeded preferred values for impact hardness, indicating these ranges may be obsolete for the modern elite natural turf surface. 相似文献
The game of hurling is ranked as one of the fastest and most skilful field games in the world. It is played by a stick, hurley, made of ash wood and a ball, sliotar, made of a cork core or similar viscoelastic materials. Better standardisation of the game equipment requires analysing impacts to quantify precisely the effect of variations in equipment design on the resultant impact force at low and high striking speeds. Therefore, the purpose of the present study was to use a high-speed camera to (1) characterise the impact dynamics in term of impact force magnitude and duration, and (2) investigate whether a relationship exists between the game equipment and the magnitude of the impact force. An air cannon unit (ACU) test rig was set up to cause the sliotar to strike the hurley at predetermined speeds. A high-speed camera operating at 12,500 frames per second (fps) was used to capture 32 experimental impacts covering a range of sliotar and hurley brands, impact locations and impact speeds. The factor ??sliotar brand?? was identified as the most significant factor for the impact force among other main factors and two-factor interactions at a constant speed and it had a significant effect with up to 27?% difference between sliotar brands. It was demonstrated that, at higher impact speeds, the force?Cdeformation curves of the sliotar brands varied significantly, even though similar force?Cdeformation curves have been reported at quasi-static compression and similar COR values at low impact speeds using the standard free-drop test. This is the first known study to characterise the unique, highly non-linear and anisotropic sliotar?Churley impact using high-speed camera technology. It highlights the need for a tighter standard for sliotar materials and manufacturing to increase uniformity between different brands and strongly suggests that the standard free-drop test is not sufficient to characterise and compare game equipment. 相似文献
There are many challenges facing new librarians in the academic environment, including collection development. This article analyzes the topic of collection development and how it relates to new professionals in the field of librarianship. The article contains a literature review of papers discussing the collection development curriculum in library and information science programs, expected skills required of collection development offices, and library training programs for new librarians. The article also provides practical advise by recent graduates and their collection development experiences. Topics of discussion include acclimation to a new environment, collection development policies and procedures, liaison work, resource selection, and time management. 相似文献