In order to understand learners and players in relation to environments typically found in sport, it is necessary to first understand the individual as an information processor who must sample information from the environment, interpret it, organize or select an appropriate motor response, and execute that response. One of the most difficult processing tasks in sport is motion prediction. To examine motion prediction it is necessary to consider factors about the individual, the environment, and characteristics of the object which affect the successful completion of the goal. The factors about the individual which necessitate prediction are processing, delays, movement organization, reaction time, and movement time. It is also necessary to consider other variables such as depth perception, just noticeable difference, age, and experience. Aspects of the environment which affect performance are the number of potentially relevant stimuli in the environment, the placement of stimuli in the environment, the size of the display, the complexity of the background, the signal-to-noise ratio, and the degree of prominance of the regulatory stimuli. It is also possible to make some tentative statements on the effect of object characteristics on performance. Variables which may be considered are speed, direction, angle, viewing time, prediction distance, and object flight characteristics. Knowledge of the characteristics and effects of these three factors should aid teachers in facilitating learning and performance in skills. (BD)