An information-processing view of perceptual motor performance holds that the processes involved in perception are organizational and depend on past experiences. In motor tasks which require anticipation, an individual uses past experience to predict what may happen. Yet bias effects in perceptual judgments, including bias caused by contextual stimuli, may explain the significant differences in coincidence-anticipation performance due to stimulus speed so often found in previous research. This study observed the relationship between stimulus context and performance on an anticipatory motor skill after extended practice by skilled subjects. Two groups of 20 female college athletes each were tested for their reaction to coincidence-anticipation tasks. Following four days of practice, one group was transferred to the same stimulus speeds given to the other group. Results showed that each group improved during the training, although the pattern of improvement was not identical. Both groups demonstrated a significant tendency to respond late as well as less accurately and more variably to the slowest speed. The groups performed similarly except that the transferred group was significantly later in responding to the slowest speed. A significant speed factor for constant error and individual trial means indicated subjects were influenced by contextual stimuli. Bias effects therefore seem to persist, even after extended practice. (Author/CJ)