Jackie Griffin and Stephanie Just detail their co-assessment practices using formative and summative assessments. They highlight the importance of knowing and understanding learning benchmarks in order to create appropriate assessments, discussing with team members when assessments are needed, and spending time analyzing data together with their co-teaching partners to plan future instruction. They emphasize providing a variety of assessments for students to demonstrate their learning, focusing on lessons that provide practice using the four language domains to assess language development, and using backward planning to ensure both content and language are being addressed.