Classroom-based assessments are important resources for teachers and reading specialists for informing instruction. Their benefits can be enhanced by designing measures that assess more than single skills, that follow formative assessment principles, and that involve multimodal formats and student responses. Because of the diversity in K-6 classrooms, teachers must know what students bring to learning situations, what they are looking for in all students' performance, and how to tailor instruction that will promote the higher level thinking needed to meet the educational challenges confronting them.