Structural equation modeling of relationships among developmental skills and writing skills in primary- and intermediate-grade writers.

We used multiple-group structural equation modeling to analyze structural relationships between latent factors underlying writing-related developmental skills and component writing skills in Grades 1-6. For handwriting, both motor skills and orthographic coding contributed to the model fit, but only the path from orthographic coding was significant at all grade levels. For spelling, only the path from orthographic coding was significant in the primary grades, but both that path and the path from phonological coding were significant in the intermediate grades. For compositional quality, both reading and oral language contributed in the primary grades but the model was unclear in the intermediate grades because of high covariance between those factors