جستجوی مقالات مرتبط با کلیدواژه « Random Practice » در نشریات گروه « تربیت بدنی »

The purpose of present study was to test the effect of contextual interference and self-regulation on the transfer of volleyball services (underhand and windmill service).

Participants were 39 male students (20-25 years old) were randomly assigned to one of three groups (blocked, random and self-regulation) and performed total of 40 trials of volleyball service each session (6 sessions). The blocked group practiced 40 trials of one service each session but the random group randomly practiced both services. In self-regulated group, the type of services in each session was determined by subjects. The transfer test was conducted one week after practice period in 5 trials. In order to analyze the data, the one-way analysis of variance and the Tukey’s post hoc tests were used.

The comparison between the pre-test and transfer test showed that the difference between blocked and random groups was not statically significant. The  self-regulation group had higher transfer scores compared to blocked and random groups.

The results of present work support the contexuual interference affect but it’s not significant. Self-regulated practices involve the subjects in learning processes. Also, with his method, they participate more activity in determining the characteristics of the exercise. These factors lead to the improvement of learning and better performance.

This study was aimed to compare the effect of two methods of variability (contextual interference and differential learning) on the learning in golf putting. For this purpose, 50 female students (mean age 21.6 ± 1.7) were randomly divided into five groups, including blocked contextual interference (BCI), random contextual interference (RCI), blocked differential learning (BDR), random differential learning (RDR), and control. After a pre-test, participants practiced the putting task for three consecutive days (10 blocks per day, 12 trails each) according to their grouping. Ten minutes and 72 hours after the last practice session, the immediate and delayed retention tests were performed, respectively. Also, the participants completed a transfer test. Results for the retention tests did not show a significant difference between differential learning groups and the random contextual interference group (p > 0.05), while during the transfer phase, differential learning groups showed higher accuracy (p < 0.05). Therefore, the continuous changes in differential learning Probably for reasons like the emergence of the subject and context-dependent attractors also the phenomenon of Stochastic perturbations seems to be more generalizable than the pattern created by contextual interference.

The aim of this study was to investigate the role of the errorless, errorful and random practice schedules on the acquisition and learning of relative timing in a motor task. 51 male students (age: 22±4 years old) were selected and randomly assigned to four groups (control, errorful, errorless, and random). This study was carried out in five phases: pretest (PRT), acquisition (ACQ), 10-min retention and transfer and 24-hour retention and transfer. In the acquisition phase, a timing task with three different difficulty levels (simple, moderate, and difficult) was practiced in three sessions of 45 trials with feedback by experimental groups. In order to analyze the data, a mixed-design analysis of variance model with repeated measures on each variable was used in the acquisition and retention phases. The one-way analysis of variance (ANOVA) was used in the other phases. The findings of relative timing showed no significant differences among the groups in the pretest (P˃0.05). Additionally, in retention and transfer tests, errorless group had better performance than errorful, random and control groups (P≤0.05). Errorless group performed better than the random and errorful groups in 24-hour transfer test of the secondary task (P≤0.05). These results showed that practice in errorless conditions leads to a better learning of the task and its generalization to new conditions that are consistent with the implicit learning and reinvestment theories

The purpose of this study was to investigate changes in mental representation in golf putting task due to random and blocked practice. Thirty participants were divided into random, blocked and control groups. First, the initial mental representation level of participants was measured and they performed 18 trials as retention. Then, they practiced the intended task for six consecutive days. A week after the last practice session their final mental representation level was measured and performed 18 trials as retention test. Results showed that random group had more errors than blocked group during acquisition, but performed more accurate than this group during retention. In addition, it was showed that random group has a more structured mental representation than the blocked group and this representation is more like the skilled participants.

The aim of the present study was to investigate the effect of contextual interference on balance of mentally retarded people. For this purpose, 40 educable and mentally retarded boys in Qazvin city (mean age 24.45 ± 3.120) were randomly divided into two groups: blocked and random practice. After the pretest, given their practice arrangement, subjects in each group performed their workout for 4 weeks (3 sessions per week) as the acquisition phase. Acquisition test was conducted in the last session, and then retention and transfer tests were performed after 48 hours. After Kolmogorov-Smirnov test verified normal data distribution and Leven test examined the homogeneity of variances, analysis of variance with repeated measures showed that the intervention was effective and the groups significantly improved (P=0.0005). The results of the independent t test (to compare two groups in static balance) showed that random practice group performed better in retention test (P=0.007) whereas no significant differences were observed between the groups in transfer test (P=0.061). In addition, dynamic balance results showed that random practice group performed better than the blocked practice group and it had a significant difference in retention and transfer tests (respectively P=0.001, P=0.002). So, mentally retarded people can use the beneficial effects of random practice.

This study aimed at investigating the effect of blocked, incremental systematic and random contextual interferences on acquisition, retention and transfer of volleyball skills based on changes in a generalized motor program. In fact, this study was conducted to answer this question that whether regular increment of contextual interference level is more effective on learning volleyball service skill than blocked or random practice schedules. 30 students (mean age 23±4 yr, 3 groups and each 10 subjects) participated in this study. The groups were different in practices of the three services. Subjects performed simple, overhead and single arm skills from a distance (9 m from the volleyball net) with different practices. Each participant practiced 108 trials of each service, totally 324 trials during 9 sessions (each session 36 trials). The results indicated that incremental practice resulted in a better performance in retention and transfer tests than blocked and random practices (P˂0.05). In general, it was suggested that the practice should be scheduled so that it can start from low interference and gradually and systematically continues towards high interference in order to facilitate learning of several generalized motor skills.

The present study aimed at determining the relationship between learning styles and the effect of random and blocked practices on learning of badminton serve skills. In this quasi-experimental study، 48 female high school students were randomly placed in four groups: 1. convergent learning style with random practice، 2. convergent learning style with blocked practice، 3. divergent learning style with random practice and 4. divergent learning style with blocked practice. After the pretest، subjects went through the acquisition phase under specific conditions of each group and then participated in retention and transfer tests. Kolb Learning Styles Questionnaire (KLSI) and French short serve test and Scott and Fox high serve tests were used. ANOVA was used to compare the scores of the four groups. Findings showed differences among immediate retention، delayed retention and learning transfer (P<0. 05). Convergent learning style and random practice were more effective than divergent learning style and blocked practice to learn badminton serve skill (P<0. 01). Therefore، focusing on the role of learning styles and learning intervention in instructing serve skills gains importance.

This study aimed at investigating the effect of the type of feedback and practice on the acquisition of parameter index. For this purpose, 8 groups (each 12 subjects) were formed: constant practice group with self–controlled feedback, constant practice group with yoked feedback (yoked group), blocked practice group with self–controlled feedback, blocked practice group with yoked feedback, random practice group with self–controlled feedback, random practice group with yoked feedback, serial practice group with self–controlled feedback and serial practice group with yoked feedback. The subjects threw towards a circle drawn on the ground with closed eyes from a 3m distance with the score range from 10 to 100 (failing to throw in the circle meant no score). The data were analyzed using mixed factorial analysis of variance and one-way analysis of variance (P<0.05). In the retention test, the self–controlled feedback prioritized the yoked feedback (P<0.05); however, the effect of practice type was not observed (P>0.05), that is, there was no difference between practice in contextual interference condition and practice in constant condition. The results observed in the transfer test were contrary to those observed in retention test, that is, the effect of feedback type was not observed (P>0.05). The results also showed that the children did not reach the final stage of self-regulation (i.e. generalization) while the effect of practice type was observed (P<0.05) and the practice groups in contextual interference condition were superior. Also, there was no statistically significant difference among practice groups in contextual interference condition (i.e. blocked, serial and random practice groups) in all acquisition stages. Overall, this study showed the beneficial effect of self–controlled feedback in the retention test and practice in contextual interference condition in the transfer test in children. As there was no difference among practice groups in contextual interference condition, the present results confirmed Magill and Hall's (1990) second hypothesis, because the effect of contextual interference was not observed in a similar motor program.

The aim of this study was to compare the effects of random and blocked practices with respect to the changes in generalized motor program (GMP) and parameter on acquisition، retention and transfer of table tennis service. For this purpose، 32 subjects were randomly assigned to four groups (8 subjects each group). In the first two groups، GMP changed with blocked and random arrangements while in the last two groups، parameter changed with those arrangements. After pretest، participants completed 300 trials in each task (totally 900 trials) and then they participated in posttest، retention and two transfer tests with different aims. The data were analyzed by two-way ANOVA and ANOVA with repeated measures (P˂0. 05) and Bonferroni post hoc test was used to mark the differences of the groups. The findings showed that despite the type of changes، the random practice caused better performance than blocked practice and these advantages of random practice in GMP changes were greater. However، these effects not only were observed in the same situation but also were maintained in other contexts. In addition، these effects not only influenced performance but also caused the participants to perform the tasks with more efficiency، more cognitive effort and less attention.

Contextual Interference is defined as interference in performance and learning that arise from practicing one task in the context of other tasks. Transitional practice is a kind of practice sequence that starts out with trials of large blocks; then moves to smaller random blocks، and eventually finishes with complete randomization. The aim of this study was to investigate the effect of ‘transitional practice schedule’ on contextual interference in learning three badminton skills. The research was quasi-experimental with three experimental groups. The subjects were 30 female students of physical education (age: 19±1. 3) from Urmia University who voluntarily participated in the study. They practiced three badminton skills (long service، forehand toss and backhand toss strokes) for ten sessions. In each session، each subject practiced 15 trials for each skill and totally 45 trials. The blocked group practiced in a blocked format. The random group practiced all three skills randomly in a way that no two similar skills would be repeated one after the other in each sequence. The transitional practice group practiced the first three sessions in a blocked format، the next three sessions with five random trials، the next three sessions with three random trials and the last session in an entirely random format. The groups'' performances were recorded in each session. After the ten sessions، the immediate retention test and after 48 hours with no practice، the delayed retention test was conducted. The data were analyzed by one-way analysis of variance with repeated measures (ANOVA). The results showed that in the acquisition stage، group differences were not significant (p=0. 48)، but the mutual reaction (practice sessions x groups) was significant (p=0. 001). In immediate retention test، only the difference between the block and random groups was significant (p=0. 005) and the blocked group performed better than the random group. In delayed retention test، both random and transitional groups performed significantly better than the block group (p=0. 001). Transitional group performed better than the random group and this difference was significant (p=0. 043).

This research aims at studying the effect of different Practice Schedules (Blocked, Random, and systematically increasing) on acquisition, retention and transfer different basketball pass Species (overhead, chest and single arm). Subjects included 45 secondary male students (Mean age 17.14± 0.75) whom were assigned into three matched groups Blocked, Random and systematically increasing (its mention increasing systematically contextual interference to in training duration) following pretest. The subjects didn’t have any experience in playing basketball. At the determined and given condition for each group, subjects performed the task for 9 sessions; 9 trials in each session. After 24 hour, retention and transfer tests with 4 trials in each pass were taken. Results showed effect of practice session was significant but no significant difference in acquisition between groups. In retention and transfer tests, there were significant differences between mean scores of practice groups, that supported Magill and Hall theory (1990) and challenge point idea of Guadagnoli and Lee (2004).

The purpose of this study was to examine the effect of contextual interference on learning discrete and continuous motor tasks with the same and different generalized motor programs, with the meta-analysis approach. studies as an electronic search and manual search (in reservoirs thesis of University of Tehran, Shahid Beheshti University, Tarbiat Moalem Tehran and Shahid Chamran Ahvaz) were collected. In present study, 18 studies were selected for analysis. Experiments conducted in these studies were divided into four categories based on task type: a) experiments with discrete tasks with same generalized motor programs, b) experiments with discrete tasks with different generalized motor programs, c) experiments with continuous tasks with same generalized motor programs and d) experiments with continuous tasks with different generalized motor programs. The results of this meta-analysis showed that contextual interference had devastative effects on performance in the acquisition phase in all four experiment categories. But contextual interference was created better performance in retention phase in all four experiment categories. The contextual interference had beneficial effects in experiments with discrete tasks with different generalized motor program and continuous tasks with same generalized motor program. In transfer phase, contextual interference had not been created significance effect on performance in experiments with discrete tasks with same generalized motor program and created devastative effect on performance in experiment with continuous tasks with different generalized motor program. Results revealed that the contextual interference effects are different in continuous and discrete tasks with different and same generalized motor programs.

The purpose of the present research was to examine the effect of practice arrangement on retention and acquisition of generalized motor program of throwing skills in decathlon (shot-put, discus and javelin throwing).

40 right-hand and novice male student (age: 19-23 years) voluntarily selected and randomly assigned in two groups of random and blocked practice. Subjects, after performing one block in the pre-test, exercised two blocks for nine sessions in acquisition phase, performed one block in acquisition test, and after 72 hours performed one block with randomize blocks, for retention test. Each block included 9 trials.

The analysis of mixed ANOVA with repeated measures for factor of sessions of practice in acquisition phase showed that two groups progressed during acquisition phase and blocked group was better then random group in all of practice sessions. Also, independent t-test showed that blocked group is significantly better than random group in acquisition test, but random group significantly better than blocked group in retention test (p<0.05).

These results show that contextual interference has positive effect on skills controlled with different generalized motor program. Therefore, findings of this research support from Magill and Hall (1990) hypothesis and action plan reconstruction hypothesis of Lee and Magill (1985).

This research has considered the effect of retroactive inhibition on contextual interference in acquisition, retention, and transfer.Three independent blocked groups, blocked without retroactive inhibition (BL-without), blocked with 18 trials of retroactive inhibition (BL-18), and blocked with 36 trials of retroactive inhibition (BL-36), were created that varied in order of presentation of tasks. By testing a single task in retention and creating three independent blocked groups, varying amounts of retroactive inhibition were produced. This isolated the effects of retroactive inhibition on blocked compared to control and random subject's retention. Male students of Amirkabir university of Tehran were population of this investigation. Seventy-five subjects (M=26, SD=3.18) who had evaluated themselves as not experienced in sport skills were selected randomly and fifteen subjects were randomly assigned to the five groups (random, control and three block groups).Findings of this research have shown that random group in acquisition have perform so weak and it was so different and positive in retention and transfer.The results support previous contextual interference findings and suggest that retroactive inhibition influences the retention deficits demonstrated by blocked compared to random subjects.