Students with literacy-based learning disabilities (LBLD) experience difficulties with a variety of literacy tasks. Despite overwhelming evidence that students with LBLD generally struggle with writing, most studies have focused on these students' reading skills. This pattern persists though writing may be even more challenging for this population than reading. In addition, research on students with LBLD generally focuses on elementary-school students. Yet findings from these studies may not apply to middle-school students because of cognitive and social differences and the increasing complexity of literacy tasks. Enduring difficulties with literacy may interfere with students' ability to meet school requirements, express themselves through writing, and succeed in a world that increasingly relies on distanced communication.

Guided by the assertion that reading and writing are distinct yet fundamentally-related aspects of literacy, this dissertation focuses on both the reading and writing skills of middle-school students with LBLD. The first study explored differences in participants' performance on four measures of word reading and investigated whether one measure best predicted participants' reading comprehension skills. Participants performed significantly better on accuracy measures than fluency measures. Also, real word reading measures were better predictors of reading comprehension than nonword measures.

The second study investigated the relationship between component writing skills and writing quality. Spelling ability was found to be a positive predictor of writing quality. Also, an interaction was found between spelling ability and word choice, suggesting that the words students use in their essays play a mediating role on the effect of spelling ability on writing quality. Poor spelling skills may induce students to use easier words, thus reducing the perceived quality of their essays.

The third study identified two factors underlying text production: content generation and mechanics. Using a path analysis, I found that content generation mediated the effect of mechanics on writing quality. Mechanics had no direct effect on quality, but had a strong effect on content generation which in turn had a strong effect on writing quality. Results of this dissertation lay a foundation for future research on the understudied population of students with LBLD and suggest potential targets for intervention.