Dynamical systems theory proposes that team sport is a complex system, with many independent, but interacting components that vary over space and time. Here, skill learning and execution are the functionality of the player-environment, where the constantly changing environment affords the player(s) opportunities to act. It is ultimately the ability of the player to interact and adapt with the changing environment (this includes teammates, and opposition players) and the constraints of the task to achieve its purpose (for example, beating the attacker). Based on this theory, the task and environmental constraints of training or testing should provide valid perceptual cues and be representative of the conditions in a competitive match environment.
Ecological validity refers to the empirical relationship between a cue (i.e. perceptual variable) or a series of imperfect cues to infer or predict future actions towards achieving a goal. In other words, this is the way in which skilled players use available information or cues from their opponents and environment to predict future actions before their own movements are initiated.
Representative design refers to the arrangement of conditions and constraints of an experimental, learning, or testing environment so that the conditions or constraints represent the performance environment to which the results are intended to apply.
Skills and actions executed in a testing or training environment should be able to easily transfer to the performance environment (known as action fidelity).
Both ecological validity and representative design exist on a (distinct) continuous scale, and not in absolute terms . If full teams competing against each other are considered the complete system, sub-systems at different levels of interaction between teammates, opponents and the immediate task exist. The simplest of these subsystems is the interaction between an attacker and defender. From an ecological validity and representative design point of view, 1 vs 1 attacker and defender interactions are also the easiest to study. Building on from the 1 vs 1, to 3 vs 3, 5 vs 5 and so on, the interactions between teammates and opposing players become more complex, and perhaps harder to study from an ecological validity and representative design perspective. Furthermore, as one progress through the sub-phases, from 1 vs 1, to team vs team interactions, players’ behaviours become more stable and predictable as decisions may also be pre-planned based on team goals (i.e team tactics and strategy) and not the environment alone. This is not to say that player’s will not adapt to their immediate environment and act accordingly.
Player well-being during a training and testing is of utmost importance. Needless to say, that a skill training or testing should present a player with minimal risk of injury. Rugby is a full contact sport, with higher risk of injury compared to many other team sports . During a match, the correct execution of contact skills allows players to tolerate frequent high impact physical contact situations like the tackle.
Keeping ecological validity and representative design in mind, it should be noted that coaches and players are reluctant to engage in full, match-like contact for training or testing because of the risk of injury. With that said, contact skills are an essential part of safe participation and performance in Rugby, and therefore cannot be neglected.
Even though Dynamic Systems theory predicates that during competition a player’s movements are emergent and variable based on the affordances of the environment, it acknowledges the existence of an approximate movement pattern, which is stable and reproducible on separate occasions, but able to vary and adapt according to the situation. This notion is particularly important for contact skills, as failure to execute certain technical actions in contact increases the risk of injury and reduces the probability of success. In other words, controlled conditions with a focus on contact technique for contact skills will benefit both the advanced and developing player.
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Araujo, D., Davids, K., and Passos, P., Ecological Validity, Representative Design, and Correspondence Between Experimental Task Constraints and Behavioral Setting: Comment on Rogers, Kadar, and Costall, Ecological Psychology, 2007, 19, 69-78.
Passos, P., Araújo, D., Davids, K., and Shuttleworth, R., Manipulating Constraints to Train Decision Making in Rugby Union, International Journal of Sports Science and Coaching, 2008, 3(1), 125–140.
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Hendricks, S., Lambert, M., Masimla, H., and Durandt J., Measuring Skill in Rugby Union and Rugby League as part of the Standard Team Testing Battery, International Journal of Sports Science and Coaching, 2015. In press.