This protocol guided the review of research that informed the recommendations contained in the What Works Clearinghouse (WWC) practice guide "Teaching Elementary School Students to Be Effective Writers." This protocol was developed to reflect standard WWC procedures for reviewing research. The protocol also was informed by the objectives identified in the guide's formal purpose statement, which states the guide's goal is to provide evidence-based recommendations for improving elementary school students' writing. The purpose statement identifies key questions to be addressed by the panel, including: (1) How should teachers and schools create a climate to encourage writing?; (2) How should teachers customize or differentiate writing instruction for students in different grades and of different writing abilities?; (3) How should teachers help students acquire a process to think about what to write?; (4) How much time should students spend on writing, and under what conditions? and (5) How should teachers and schools employ technology to improve writing instruction? The panel sought to identify research that examined these and other issues related to the quality of students' writing.