CONTEXTUAL INTERFERENCE EFFECTS WITH SKILLED BASEBALL PLAYERS

The learning benefits of contextual interference have been frequently demonstrated in different settings using novice learners. The purpose of the present study was to test such effects with skilled athletic pe rformers. Scheduling differences for biweekly additional (''extra'') b atting-practice sessions of a collegiate baseball team were examined. 30 players (ns = 10) were blocked on skill and then randomly assigned to one of three groups. The random and blocked groups received 2 addit ional batting-practice sessions each week for 6 wk. (12 sessions), whi le the control group received no additional practice. The extra sessio ns consisted of 45 pitches, 15 fastballs, 15 curveballs, and 15 change -up pitches. The random group received these pitches in a random order , while the blocked group received all 15 of one type, then 15 of the next type, and finally 15 of the last type of pitch in a blocked fashi on. All subjects received a pretest of 45 randomly presented pitches o f the three varieties. After 6 wk. of extra batting practice, all subj ects received two transfer tests, each of 45 trials; one was presented randomly and one blocked. The transfer tests were counterbalanced acr oss subjects. Pretest analysis showed no significant differences among groups. On both the random and blocked transfer tests, however, the r andom group performed with reliably higher scores than the blocked gro up, who performed better than the control group. When comparing the pr etest to the random transfer test, the random group improved 56.7%, th e blocked group 24.8%, and the control group only 6.2%. These findings demonstrate the contextual interference effect to be robust and benef icial even to skilled learners in a complex sport setting.