Summary.Ten ‘informal’ and ten ‘comparison’ primary grade classrooms matched according to socio‐economic neighbourhood, grade, and instructional organisation were observed using the Pupil Activity Scan, an observation instrument specifically designed for the present study to record pupil behaviour. Analysis of the observational data indicated that children in informal classes engaged in child‐to‐child interaction, play activities, individual conferences with the teacher, and independent work to a greater extent than comparison pupils. In the comparison classrooms, word analysis activities, printing activities, independent silent reading, and teacher‐led group experiences were more prevalent. Substantial variation in curricula was also observed across all classrooms. Testing of the children at the end of the school year indicated no differences between the two groups in language development, problem‐solving, fine motor‐figural perception, role‐taking, or understanding of classification, but the performance of pupils in the informal classrooms appeared to be lower with respect to re