We had 3 aims in the present study: (a) to examine the dimensionality of various evaluative approaches to scoring writing samples (e.g., quality, productivity, and curriculum-based measurement [CBM] writing scoring), (b) to investigate unique language and cognitive predictors of the identified dimensions, and (c) to examine gender gap in the identified dimensions of writing. These questions were addressed using data from 2nd- and 3rd-grade students (N = 494). Data were analyzed using confirmatory factor analysis and multilevel modeling. Results showed that writing quality, productivity, and CBM scoring were dissociable constructs but that writing quality and CBM scoring were highly related (r = 0.82). Language and cognitive predictors differed among the writing outcomes. Boys had lower writing scores than girls even after accounting for language, reading, attention, spelling, handwriting automaticity, and rapid automatized naming. Results are discussed in light of writing evaluation and a developmental model of writing. [This article was published in "Journal of Educational Psychology" (EJ1055888).]