While basic elements of program quality such as teacher education, class size, and classroom materials are important,
their significance is measured in part by the extent to which they facilitate effective teacher–child interactions.
Research shows that the classroom interactional components measured by the CLASS are more powerful predictors of
children’s development and learning than are structural elements of program quality (Mashburn et al., 2008). Factors
such as teacher qualifications and class size, though important, are not sufficient in and of themselves to ensure
children’s positive development.