Despite increasing pressure for children to learn to write at younger ages, there are many unanswered questions about composition skills in early elementary school. The goal of this research was to examine the dimensionality of composition skills in kindergarten children, thereby adding to current knowledge about the measurement of young children's writing and its component skills. The writing of 282 kindergarten children were assessed using three different scoring methods. Confirmatory factor analyses were used to investigate the dimensionality of various methods of scoring. Results indicated that a qualitative scoring system and a productivity scoring system capture distinct dimensions of kindergartners' compositions. A scoring system for curriculum-based measurement could not attain acceptable fit, which may suggest that CBM is ill-suited for capturing the important components of composition for kindergartners. This study indicated that the measurement and components of composition in kindergarten may be qualitatively different from the compositions of older children. [For the corresponding grantee submission, see ED605728.]