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The purpose of this study was the comparison of the required time and repetition for the acquisition of simple and complex timed motor sequenced task (TMST) among various practical conditions and determination of suitable practical methods with respect to individual characteristics. One hundred and fourteen university students, with the age range of 19-25 years old, were divided in 4 groups  according to Raven Intelligence test, Achievement Motivation Test, Reaction time and Purdue pegboard, and based on the first, second and third quadrants. Then they were randomly placed in one of the two groups of simple and complex TMST and also in one of the practical conditions of the interaction of the organization of practice (random, blocked, constant), and practical distribution (massed, distributed). The subjects trained 6 days under their specific practical condition of simple or complex TMST, in a way they reached to the acquisition criterion (accuracy %75, timing %25, stability %15) in a practical training block. The number of repetitions and passage of time before this criterion block were considered as the minimum required time and repetition for acquisition of TMST. The data were analyzed using two-factor analysis of variance, independent t-test and Xi - 2 test (=&alpha0.1). The results showed individuals with different characteristics have acquired simple TMST in blocked and  massed condition (except group ) in average within 30 repetitions and 1347 minutes, and complex TMST in random and distributed condition (except group ) in 25 repetitions and 1228 minutes. In addition, the findings showed that the principles of practical programming is affected by both the complexity level of task and individual characteristics. At last, it seems there is a need of more studies on the combination effect of the environment, individual and task on the acquisition fine motor skills. 

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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.

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The aim of this research was to determine the effect of different training environments, type of skills and interactions on open and closed skills. The statistical  population was all students living in dormitories of Tehran University in the 88-89  academic year. The sample was 60 people selected based on convenience sampling methods among students who had no experience in badminton skills (Long Service and clear). Based on pre-test subjects were matched in six groups of ten persons (noncompetitive, competitive, and combined). All of six groups performed a practice in defined medium for 10 sessions and each session were performed 40 times. The long-service tests were used to measure open badminton skill and clear test was performed to measure closed skill. Test scores of subjects were computed based on the mean of ten hits score. Descriptive statistics were used to determine the mean and standard deviations and to test research hypothesis, a two-way analysis of variance (ANOVA) with repeated measures and independent t-test were utilized. The result of ANOVA showed that exercise in each of the training environment increased acquisition and retention of each skill, but the levels are different (p<0.05). Also, Factorial ANOVA showed that the skills and environments does not have meaningful effects on acquisition and retention of skills while each skill interacts significantly with the training environment (p<0.05). In addition, exercising each of the skills in the same environments had different levels of acquisition and retention.

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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. 

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The aim of this study was to investigate simultaneous changes in EMG pattern during learning dart skill in dominant and non-dominant hands. The samples consisted of 10 non-athlete students with an average age of 23±2.5, which were divided into two group dominant hand (5) and non-dominant hand (5). Repeated measures ANOVA were used to measure data at the execution level and changes in EMG activity. The results showed a significant decrease in the absolute error of dart throwing at the performance level and an increase in EMG activity at the muscle level along with a decrease in muscle co-contraction in the acquisition and retention stages in both groups (P<.05). Also, there was no significant difference between EMG activity in the dominant and non-dominant hand groups after skill acquisition (P>.05). Generally, the results of this study showed that along with relatively constant changes in performance during dart skill learning, relatively constant changes in EMG patterns also occur, so that the concept of motor learning is also observed at the muscle level. Also, the results of this study supported the existence of the same motor program for dominant and non-dominant hand control, even in the conditions of bilateral transfer control.

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The purpose of the present study was to investigate the effect of visual illusion and attention instructions on golf putting performance and impact learning in children. The method of this study was quasi-experimental and applied in terms of purpose and one of the intra-group projects. A total of 48 students with a mean age (7-9) years were selected by random sampling method and assigned to four groups of attention instructions (external, internal), visual error (large, small). The measuring instrument used in this study was the Ebbinghaus error displayed on the ground and the golf ball for throwing towards the target. This research was performed in different stages of pre-test, acquisition, retention and transfer (with 24 hours of untested training). In data analysis, combined analysis of varianceand Bonferroni post hoc test were used. The results showed that the effects of visual hallucinations and attention instruction had a significant effect on golf blow learning in all stages, so that the two groups of external attention with a large and small perceived goal had better performance than the other groups and in the second stage of secondary task transfer. Participants with two conditions of internal attention with large and small visual hallucinations had severe dysfunction, while the group of external attention with large and small visual hallucinations alone was relatively stable. The results showed the importance of external attention and the dual effect of visual hallucinations, which may be a tool for tacit learning, and visual hallucinations may not always be necessary in learning skills. It is recommended that physical education instructors use the psychological variables of attention, external attention and hallucinations in the training of pot golf field skills.