The perception and identification of technical errors during skill execution is a critical component in coaching, because it provides the foundation for skill analysis, instruction, and feedback provision. In this study, we examined the influences of perceptual and motor experience on the perception of kinematic change in a technical evaluation task that is common in coaching. A total of 21 expert coaches, stratified by playing ("motor") expertise, as well as ten novice coaches and ten current players, observed video and point-light displays of a service action and recorded written judgments on whether the serve had changed from one video clip to the next. Three kinematic variables were manipulated: maximum knee flexion, maximum trunk rotation, and ball toss position at zenith. Coaching experience provided no additional benefit when perceiving global (holistic) changes in the service action, and limited if any benefit when perceiving specific changes in the observed kinematics. A significant expertise effect showed that expert coaches have increased sensitivity when detecting smaller changes in knee flexion. Changes in trunk rotation appeared difficult to perceive for all groups, whereas changes in lateral ball toss position were easily perceived. Motor experience did not influence the perception of global kinematics and provided no benefit above perceptual experience alone when perceiving specific kinematic changes. Collectively, the findings demonstrate that experienced coaches have the capacity to detect relatively small changes in kinematics; however, the ability to detect changes does not appear to be influenced by the extent of their own expertise in producing the movement pattern being evaluated.
Keywords: Coaching; Error detection; Kinematics; Motor expertise; Perception.