EXPERT PERCEPTION AND DECISION-MAKING IN BASEBALL

The paper is concerned with the nature of expert perception in a fast- action skill, baseball batting. In particular we were interested in un derstanding 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 pa rticipated in the two experiments as either an expert (N = 15) or novi ce (N = 15) batter based on their experience and batting statistics. E xperiment 1 provided displays of pitching, with batters providing a de cision time response (which removed the display), and also reporting a Prediction of where the ball would pars through the strike zone. Furt her, batters were tested on their ability to set probabilities about t he forthcoming pitch, and how this might affect batting performance. E xperiment 2 examined the use of information throughout the pitch with occlusion of the information in the display at five points before (adv ance cues) and during the ball flight. Accuracy of prediction was meas ured in this experiment to establish the value of the information to t he 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 str ategic game information to set probabilities about the forthcoming pit ch and significantly improve performance on that pitch. Results in Exp eriment 2 were less conclusive, with experts generally showing an incr ease in accuracy throughout the pitch occlusion stages, but without an expected greater accuracy for cues provided in advance of the movemen t 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 pitch recognition. It is shown, then, that attention t o 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. Further this ability is improved with the correct setting of a probability about the forthcoming pitch. These re sults support the proposal for the development of sophisticated Knowle dge structure which can make use of particular cues in the display to guide both perception and action.