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To assess differences between the Vertec and the Just Jump Systems in measuring height of vertical jump, 248 boys and 232 girls between 7 and 11 years were required to perform four maximal countermovement vertical jumps. A maximum of the four trials recorded was the dependent variable. Each vertical jump was simultaneously evaluated by each measuring device and a paired t test indicated the systems were significantly different; however, the experiment wise difference of .93 in has no practical value. The Just Jump System seems a viable alternative. Advantages and potential pitfalls regarding the use of each system are discussed.

34 beginning and 16 intermediate players were required to view film clips which showed a player serving. The film was edited so the subject would see only a limited part of the service motion and/or ball flight. The four restricted viewing conditions were as follows: 10 msec, before contact (Prior), 0 msec. (Contact), 15 msec, after contact (Immediate), and 30 msec. after contact (Flight). Based on the limited visual information, the subject indicated on a specially designed score sheet the position in which the serve landed in the deuce service court (both latitude and longitude). Analyses of variance for mean percent correct responses indicated that intermediate players were significantly more successful in plotting the latitude of the ball's position than were the beginners. Longer viewing times significantly improved both groups' ability to predict the terminal location of the ball.

45 males and 45 females between 7 and 8 years of age were acquired to catch rubber playground balls which varied in both size and color. Prior to the administration of the criterion catch test, subjects indicated their choice for a preferred color ball. Analysis indicated that the 6-in. balls (diameter) were caught significantly better than were 10-in. balls. Although the main effect of ball color was nonsignificant, the children caught balls of preferred color significantly better than those of non-preferred colors. Males scored significantly higher than the females on the catching task.

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