| dc.description.abstract | Soccer is one of the biggest sports in the world, and the level of expertise at the top
level is high. The development of this level of expertise takes time, but it also depends
on the quality of practice. The purpose of this research thesis was to systematically
review how practice schedules in Soccer affects learning, differing in degrees of
contextual interference (CI). A secondary method was included, a meta-analysis, to
determine the magnitude of the relationship, between the degree of Ci and learning.
Meta analysis calculate a total effect of studies, and therefore is a better estimate than a
single study. The CI effect, first noted by Battig (1966), states that a high degree of CI
facilitates the application of learning. A suggestion, is a division along two continuums,
describing the degree of contextual interference and variability in practice schedules
(Williams & Hodges, 2005). Both the degree of CI and variability is affected by the
demands in the practice schedule, where higher degree is more demandable (Shea &
Morgan, 1979). CI is used as the common term for both contextual interference and
variability in the remainder of this section.
This thesis included 17 studies, where 12 reported significant differences in learning,
almost exclusively in the direction of higher degree. The magnitude of relationship was
found with a large effect in general across effects, supporting the original notion of CI
effect. This general effect was homogeneous, as were the large effect of the outcome
decision making. These results are robust, and have clear practical implication. Across
moderator variables not found homogeneous in the meta-analysis, the results support
high degree of CI, including; age, outcomes, stability of environment testing procedure,
testing time point. Some studies included three practice groups, but as the meta-analysis
only can compare two practice groups, the group in the middle were both low and high
depending of the comparison. Though, were the middle group (moderate degree of CI)
compared qualitatively with the others, showing promising learning effects also
compared to higher degree, when in a stable environment of treatment. Future research
should continue to increase the depth, as this thesis and earlier research on a broader
domain (Brady, 2004) both support high degree of CI. | nb_NO |
