The Classroom Assessment Scoring System (CLASS) is an observational tool that measures classroom quality. The early learning versions of CLASS identify key behavioral interactions that reflect the quality of interactions across three broad domains: emotional support, classroom organization, and instructional support. CLASS provides valid data on teacher effectiveness, creates common language about effective teaching practices, and helps teachers understand how their classroom interactions affect student learning.
Students in classrooms that utilize CLASS show gains in receptive vocabulary, expressive vocabulary, rhyming skills, letter naming, math skills, social competence, inhibitory control, working memory, and fewer child problem behaviors. Teachers involved in CLASS coaching and professional development improve the quality of their interactions with children and increase their knowledge of skills in detecting effective interactions.