The What Works Clearinghouse (WWC) Practice Guide, "Teaching Secondary Students to Write Effectively," offers educators three specific, evidence-based recommendations that address the challenges of teaching students in grades 6-12 to write effectively. This summary focuses on the third of the three recommendations: Use assessments of student writing to inform instruction and feedback. The formative assessment cycle is a process where teachers regularly assess student skill levels, adapt instruction based on the assessment data, and then reassess skill levels. When teachers monitor student progress throughout the entire writing process, it provides helpful information for lesson planning and provides additional feedback to students. Assessment should occur on a regular basis, not just through final written products. This helps teachers better understand student progress and therefore can provide students with targeted instruction. This brief document provides steps to carry out the recommendation and identifies potential roadblocks and suggests ways to address them. [For "Teaching Secondary Students to Write Effectively. Educator's Practice Guide. What Works Clearinghouse.™ NCEE 2017-4002," see ED569984.]