Abstract：
Objectives: The relationship between task constraints and player behaviors is of interest to coaches tasked with designing practice to optimize learning. This study aims to compare the skill involvements and cooperative team behavior of teams of youth soccer players engaged in a goal exaggeration and/or a prescriptive coach instruction condition compared to a free-play control condition. Methods: Twenty male soccer players aged 12-15 participated in small-sided games under four conditions: free-play, goal exaggeration, prescriptive coach instruction, and combination over four weeks. Using video footage, teams\' collective skill involvements (shot, pass, dribble) and passing network characteristics (closeness, density, and betweenness) were measured for each game. Results: A Friedmans rank test identified that playing conditions resulted in significant differences in attempted dribbles (p < .001), goals scored (p < .001), network density (p = .001), closeness (p < .001) and betweenness (p = .002). Teams attempted to dribble the most in the free-play and goal-exaggeration conditions, and the most goals were scored in the goal-exaggeration and combination conditions. Additionally, teams exhibited more well-connected passing networks (i.e. higher density, higher closeness, and lower betweenness values) in the combination condition and higher network density in the explicit instruction condition. Conclusions: The results of this study indicate that coach instruction may be more associated with cooperative team behavior, whereas free-play or manipulating task constraints in the absence of instruction may be associated with players attempting more individual actions.
摘要：
目标：任务约束与球员行为之间的关系对于负责设计实践以优化学习的教练来说很有趣。这项研究旨在比较与自由发挥控制条件相比，参与目标夸大和/或规定性教练指导条件的青年足球运动员团队的技能参与和合作团队行为。方法:20名12-15岁的男性足球运动员在四种条件下参加小边球比赛:自由发挥,目标夸张,指导性教练指导，和组合超过四周。使用视频片段，团队集体技能参与(射击，通过,运球)和传球网络特征(紧密度，密度,和介数)对每场比赛进行测量。结果：Friedmans等级检验确定，比赛条件导致尝试运球的显着差异（p<.001），进球得分（p<.001），网络密度(p=.001)，紧密度(p<.001)和介数(p=.002)。球队试图在自由发挥和进球夸张的条件下运球最多，在进球夸张和组合条件下进球最多。此外,团队展示了更多连接良好的传球网络(即更高的密度，更紧密,和较低的介数值)在组合条件下和较高的网络密度在显式指令条件下。结论：这项研究的结果表明，教练指导可能与团队合作行为有关。而在没有指令的情况下自由发挥或操纵任务约束可能与玩家尝试更多的个人动作有关。
