Exploring the Patterns of Skill Development by Mixture Growth Modeling: Using the Batting Average Data on Professional Baseball Players

Reviewing latent growth modeling for longitudinal data and some results using this methodology on career development, mixture modeling methodologies were introduced for identifying clusters of individuals following similar developmental trajectories. For the latent growth model analysis by Amos and the groupbased trajectory model analysis using SAS Traj procedure, the batting average records of Japanese professional baseball players over ten years were selected from the published offi cial records. Results of latent growth modeling demonstrated that the quadratic form trajectory model fi t the data well. Six subgroups were also clustered by the same quadratic form using the Traj. Findings of these analyses were discussed with particular reference to the utility of the group-based trajectory modeling of mixture model methodology for analyzing career development processes.