Abstract des Autors

The paper is concerned with the nature of expert perception in a fast-action skill, baseball batting. In particular we were interested in undertanding what visual information is used by elite batters and when such information is <picked-up> by the expert through the knowledge structure that has developed for the skill. Thirty baseball players participated in the two experiments as either an expert (N = 15) or novice (N = 15) batter based on their experience and batting statistics. Experiment 1 provided displays of pitching, with batters providing a decision time response (which removed the display), and also reporting a prediction of where the ball would pass through the strike zone. Further, batters were tested on their ability to set probabilities about the forthcoming pitch, and how this might affect batting performance. Experiment 2 examined the use of information throughout the pitch with occlusion of the information in the display at five points before (advance cues) and during the ball flight. Accuracy of prediction was measured in this experiment to establish the value of the information to the point of occlusion in the display. Significantly superior scores in both decision time and accuracy scores were found for expert batters over novices in Experiment 1. Further, both groups were able to use strategic game information to set probabilities about the forthcoming pitch and significantly improve performance on that pitch. Results in Experiment 2 were less conclusive, with experts generally showing an increase in accuracy throughout the pitch occlusion stages, but without an expected greater accuracy for cues provided in advance of the movement of ball release (MOR). Of interest, however, were scores produced by both groups in early occlusion stages for different types of pitches. It would seem that the first 80 ms (approximately 3 m of ball flight) is important to pitcb recognition. lt is shown, then, that attention to the early cues provided in baseball pitching is critical to batting performance. This is supported in that experts perform faster without sacrificing accuracy, and that batters can recognize the type of pitch within 3 m of ball flight.Furtber, this ability is improved with the correct setting of a probability about the forthcoming pitch. These results support the proposal for the development of sophisticated knowledge structure which can make use of particular cues in the display to guide both perception and action. Verf.-Referat