Teachers face numerous challenges in evaluating student learning. Those new to the model-based classroom may find quizzes or exams that attempt to capture content mastery may not accurately reflect a student's overall performance in the classroom. We recognize students are doing well in MBER classrooms when they are able to apply their model ideas to new phenomena, drawing upon not only their content knowledge, but also the scientific practices related to sense-making (e.g. arguing from evidence, constructing explanations, using mathematical reasoning). Adding writing prompts that solicit student ideas around phenomena can be a great way to fairly assess student performance across the practices, but grading 150 essay questions provides its own set of challenges! Beyond incorporating evaluation during Formative Assessment, what else can teachers do?