---

The purpose of this study was to explore the effectiveness of the number of practice trials in determining the degree of task complexity. Sixty subjects according to the types of tasks (A-B) and receiving feedback (100%, omitted, self-control) were randomly divided into six groups.All of the subjects practiced 100 trials tasks in each day on first two days. Retention tests were performed during the second and third day and reacquisition tests were performed on the third day. Using ANOVA with repeated measures showed found that,all of the subjects improved across practice trials on both days but this improvement in B task was significantly better than A task on the second day. Subjects were significantly better in the second retention and reacquisition tests compare with first one’s, in addition subjects that practiced B task were better than those that practiced A task in the second retention test (p<0.05). Results indicate that A task was more complex than B task, and the optimal practice trials is required to understanding which task is complex.

---

The purpose of this study was to determine the effect of two different age groups (children and young adult) to learning of temporal-special coordination hand movement pattern. Sixty subjects according to the age (children – young adult) and receiving feedback (100%, omitted, self-control) were randomly divided into six groups. This study was done in three days. All subjects practice 100 trails of movement task in each day of first and second days. Retention tests were done in second and third days and reacquisition test was done in the third day. Analysis of variance (ANOVA) with repeated measures and two way ANOVA was used to data analysis. All participants in the first day improved their accuracy across practice trials. In the second day children did not improve their accuracy but young adult experienced improvement across practice trials. There was not significant difference between retention children tests but that was significant about young adult. During the retention tests children who received 100% feedback was significantly better than other children feedback groups and there was no significant between young adult feedback groups. During the reacquisition test children who received 100% feedback was significantly better than other children feedback groups and there was no significant between young adult feedback groups. Results from this study showed young adult are better than children in the learning of this pattern, receiving more feedback can improve motor learning in          children (in contrast with guidance hypothesis) and we must not expect motor skill acquisition occur in children like young adult.