Following professional development, 4 teachers implemented instructional lessons designed to improve the written expression of 6th- and 7th-grade struggling writers in inclusive, self-contained, and co-taught classrooms. A multiple-baseline study investigated the effects of a computer-based graphic organizer (CBGO) with embedded self-regulated learning strategies on the quantity and quality of persuasive essays by students struggling with writing. We collected data on the numbers of words, sentences, and transition words and on writing quality scores across baseline (writing without the CBGO), CBGO use (writing with the CBGO), and maintenance (writing on the computer without the CBGO) phases. Visual analysis of group average performance revealed that all students improved the quality of their writing, and the majority of students also increased the quantity of their writing. Despite teacher adherence to intervention fidelity, we discuss the quality of teacher implementation to inform future educational practice. We also discuss the relationship between student learning outcomes, classroom context, and teachers' professional development.