The perpose of this study was comparison the effect of increasing and decreasing contextual interference with the change motor program on the task of learning anticipation timing coincidence and error detection capability. For this purpose، 40 students in 4 groups participated that in each group، 10 subjects were completely random. In this research، different levels of contextual interference (block، random، increasing and decreasing) was comared with with same paramere and different motor program. Respective task was anticipation timing coinsident that was represented whit different path (change motor program). After the training، they participated in retention and transfer tests and were assessed their Absolute error detection capabilities. Data have been analyzed by statistical one way Anova، repeated measurement and toky test. The results showed that the effect of contextual interference was observed and Increasing and decreasing groups in the absolute error and error detection capabilities were significant differences with other groups. significant differences between groups for error detection capability show more cognitive effort in high interference groups that it support the hypothesis of cognitive effort Lee، Swinnen and Serrien (1994).

The purpose of this study was comparison effect of increasing and decreasing contextual interference with the change parameter on the anticipation timing coincidence task learning and error detection capability. 40 boy students (23 – 25 years old) participated in this study (10 students in each group). Subjects don’t know any thing about respective task. Different levels of contextual interference (block, random, increasing and decreasing) were comared with same motor program and different parameter. Task includes anticipation timing coinsident whit different speeds (change parameter). After the training, subjects participated in retention and transfer tests and also their absolute error were assessed. One way Anova, repeated measurement and toky tests were used for data analysis (SPSS 16). There was different significant between absolut error block group and other groups in acquisition stage (p<0.05) but there was not different significant between groups in retention and transfer stages. Results support the hypothesis Magill and Hall (1990). They believed that contextual interferenc effect was not observed with change parameter.

The present study aimed to examine the effect of contextual interference on acquisition, retention and transfer of coincidence anticipation task with constant, increasing and decreasing speeds. 36 male physical education participants from Shahid Beheshti University were voluntarily selected and randomly divided into three groups (12 subjects each group) and performed coincidence timing tasks with Bassin anticipation timing. In this research, three separate experiments were used. Experiments consisted of constant speed, increasing speed and decreasing speed. Subjects participated in pretest, acquisition, blocked retention, random retention and transfer tests. Absolute temporal errors were analyzed by one-way ANOVA, ANOVA with repeated measures and Bonferroni post hoc tests (P<0.05). Research results showed contextual interference effect in the first experiment with constant speeds in all three phases. In the second experiment with increased speeds, contextual interference effect was observed in acquisition and random retention. In the third experiment with decreased speeds, contextual interference effect was conversely observed in acquisition and blocked retention in favor of blocked group. Generally, results showed contextual interference effect in constant speeds in random retention and transfer phases while this effect was not observed in increasing speeds. This effect was observed in decreasing speeds in only blocked retention phase. Regarding interpreted cognitive difficulties in decreasing speeds due to self-tasks and also difficulty of problem solving in random groups, the results were interpreted by increasing cognitive load, difficulty of perceptive task for decreasing speeds and the effect of reducing the effect of timing errors in tasks with increasing speeds (exceptions of the speed-accuracy exchange).

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.

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 low contextual interference with high contextual interference on acquisition, retention and transfer of basic gymnastics skills in children with three to six years old. The study population included 52 children three to six years old enrolled in gymnastics school from which 20 children were selected randomly. Jumping skills (open-leg jack, closed-leg jack, pistol) balance skills (simple, stork, angel) and Tumbling forward skills (closed leg, open leg, one leg) were displayed by experienced coach and then they participated in the pre-test. Performing all pre-tests were filmed and, based on total average rating of three official refers, the subjects respectively were replaced in two groups of low contextual interference and high contextual interference(n=10). The low contextual interference group practiced only one of the skills in each session and at the end of the session acquisition post-test was taken and 48 hours later at the start of the next session the post-test of retention and transfer of last session were done and then they practiced the next skill. The high contextual interference group, practiced all the skills for the nine session in each session. At the end of the ninth session, they had acquisition post-test and 48 hours later, the retention and transfer post tests were taken. The data was analyzed by MANCOVA with alpha set at 0.05. Results showed that there were significant differences between the two block and random practice groups in all three skills of balance, jumping and tumbling(P

Age may limit the effect of contextual interference, but the accurate effect of age on contextual interference is not completely identified. Therefore, the purpose of the study was the effect of contextual interference practice orders on acquisition and learning of badminton skills of 45 female students aged from 10 to 12. Participants were randomly assigned to one of the three groups of blocked, random, and systematically increasing contextual interference. They trained three skills of badminton long serves, short serves, and forehand strokes for 10 sessions after pre-test. The tests consist of Acquisition, immediate retention, and delayed retention were taken after the fifth session, one hour after the end of the tenth session, and 48 hours after the last practice session, respectively. According to the findings of the study, in acquisition test, the blocked group achieved better scores than the random and systematically increasing groups. Although the three groups performed significantly better than pre-test scores in retention test, there was no difference among groups, meaning that contextual interference did not have positive results for children in learning badminton skills. Seemingly, due to the limitations in strategy, our participants were probably confused among the abundant information from the random practices and were not able to use the advantages of contextual interference. So, the benefits of random practice based on forgetting and elaborating hypotheses in this age group, especially regarding discrete motor skill in badminton is in doubt. The authors carefully suggest that elementary school physical education teachers should use blocked practice methods for badminton practice to help children build a suitable motor skills scheme and encourage them to repeat the desired skills because of the motivational feedback of blocked practice as a result of greater success in practice sessions.

Contextual interference is one of the instructional methods for several skills. The aim of this research was to determine the effects of interference before performance and interference during performance on the acquisition and retention of generalized motor program and parameter in basketball skills with an emphasis on the examination of contextual interference hypotheses and self-regulation learning theories. In interference before performance، self-practice schedules is generated (self-regulation effect) and interference during performance، experimenter-imposed practice schedule is generated (contextual interference effect). For this purpose، 120 students of Yazd University (age range 19-21 years old) who had no prior experience in basketball skills volunteered to participate in this study. Participants were randomly assigned to 10 groups (each 12 subjects); 5 groups practiced with generalized motor program (dribble، chest pass and free throw skills) and 5 groups practiced with parameter (free throw from different distances) in practice schedules (blocked، random، serial، self-regulated and yoked to self-regulated). To collect data، throw and pass test (AAHPERD basketball test) and dribble test (Johnson basketball test) were used. After the pretest، in the acquisition phase، subjects took part in 5 training sessions including 45 trails per session (15 trails each block) for 5 days. After 48 hours، they participated in retention test with 15 trails (5 trials each task). The data were analyzed by one-way ANOVA، factor analysis of variance with repeated measures، LSD and Duncan post hoc tests. Results showed a significant difference among practice schedules in acquisition and retention phases of generalized motor program، that is، the effect of contextual interference was observed in this program (p<0. 05). Also، there was a significant difference among the schedules in acquisition and retention phases of parameter، that is، controlling the design of practice has a positive effect on learning (p<0. 05). Thus، the results suggested that during learning process، the effect of interference before performance was more important than during performance.

This study was designed in order to investigate the effects of contextual interference (CI) in acquisition, retention and transfer of motor skills. 40 student of Tehran University (average age of 22.4±2) were voluntarily selected and randomly arranged in two experimental groups of 1 and 2 to investigate the effects and to comparise two methods of blocked practice (with low CI) and random practice (with high CI). The subjects in each group participated in 9 session of 3 kinds of volleyball serves with 378 repetitions in the acquisition phase. In 3 sessions, 45 acquisition tests were administered during the practice phase and after 5consecutive days and 7days, they participated in 15 repetitions of delayed retention test and 15 transfer tests. T test, ANOVA and repeated measure were used to analyze data. The results of the two experimental groups showed that the contextual interference effect was significant when the random group performance declined in the acquisition phase contextual interference test increased in delayed retention and transfer phases when compared with the blocked group retention test and transfer tests. These findings supported the second idea of progression of memory and different views of motor preparation with the high CI of training.

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.