They learn best through active, hands-on activities with concrete materials. Its list of developmentally appropriate practices closely matches the components of nongraded education. The inappropriate practices it lists are typical of traditional graded education. Katz and others found that participating in mixed-age groups has social and cognitive benefits for both older and younger children. Cooperative, prosocial behaviors increased and discipline problems were reduced.
Experts agree that teaching multiage classes requires more preparation time.
Teacher burnout due to insufficient planning time was one reason for the failure of earlier nongraded experiments. Most teachers will require substantial training. Districts that previously relied heavily on single sets of textbooks and manuals will need to acquire hands-on materials and a variety of supplementary books. These changes may be costly. It may be more efficient to correct multiple-choice tests than to evaluate collections of student work and write descriptive comments.