British Educational Research Journal

Disruptive behaviour in classrooms is a significant challenge for learning in schools and a risk factor for students’ academic achievement and a significant source of teachers’ work‐related stress. Earlier research shows that clear behavioural expectations, monitoring students’ adherence to them and behaviour‐specific praise are effective practices to reduce disruptive behaviour. Although behaviour problems are common in middle schools, most of the interventions have been developed and studied in elementary schools. This randomised study evaluated the effects of a class‐wide intervention on classroom behavioural climate and disruptive behaviour, on teacher‐experienced stress and on the time needed for behaviour management in middle school. The classes were selected for intervention by their teachers on the basis of poor behavioural climate. The intervention was based on teachers’ cooperation; they collectively agreed on clear behavioural expectations, used positive feedback and, if needed, applied consequences in response to high rates of disruptive behaviour. The results indicated medium to large effects on classroom behavioural climate according to teachers’ evaluations, and somewhat more inconsistent effects on classroom behavioural climate according to student evaluations and in the time needed for behaviour management. The behavioural climate of the classes remained at a constant level during the follow‐up. The intervention was well accepted by teachers and students. The results suggest that an easily applicable intervention may produce significant improvements in classroom behavioural climate in middle schools.