Does teacher professional development for implementing the Writing Pathway program improve the argumentative writing of grade 7 and 8 students?

This quasi-experiment examined if teacher professional development to implement a comprehensive writing program, Writing Pathway, improved the argumentative writing of their grade 7 and 8 students. Teachers from multiple States in the USA delivered the writing program during a full school year. Students in the Writing Pathway treatment condition were from 12 classrooms in five schools (N = 261; 49.68% female), whereas students in the business as usual control condition were from 9 classrooms in three schools (N = 180; 51.1% female). The Writing Pathway program included 174 writing activities to teach sentence level-skills (grammar, conventions, and sentence construction) as well writing production processes (planning, drafting, revising, and editing) for persuasive, informative, and narrative texts, including teaching students to write persuasive and informative texts with source materials. Grade 7 Writing Pathway students made greater gains in writing quality than controls (d = 0.59), as did grade 8 Writing Pathway students (d = 0.93). Implications for research and practice are discussed.