Assessing Change in Swimming Skills Using the Hierarchical Linear Model

Abstract

The purpose of this study was to apply the hierarchical linear model (HLM) to assess children's changes in swimming skills. A total of 20 children from a preschool swimming program, 10 boys and 10 girls, were tested by a swimming testing battery at the beginning and at the 4th, 9th, 12th, and 16th months of the program. The swimming-skill scores were analyzed using the HLM at two levels. At Level 1, children's skill levels were defined as a function of a linear growth curve. At Level 2, mean growth trajectory, individual variation in growth trajectory, and reliability of initial status and growth rates were examined first. Then, to determine the impact of the between-participant variables of gender, entry age, and previous swimming experience, parameters (initial status and growth rates) of modeling at Level 1 were defined as a function of these between-participant variables. Entry age was the only determinant found to significantly affect initial status and change in swimming kicking skill. There were, however, other unidentified factors that also contributed to the change in swimming skills. The HLM provided a useful and flexible means for studying changes in motor skills.