This study examines teachers' use and evaluation of cooperative learning al
ong with pupils' reactions to cooperative grouping and the quality of the g
roup cooperation in a sample of Dutch primary school teachers who implement
ed cooperative learning methods. Teachers reported that cooperative learnin
g occurred in their classrooms about four times a week. Teachers reported s
ocial skills, on-task behaviour and pupil self-esteem to improve as a resul
t of having pupils work in groups. The pupils reported a positive attitude
towards cooperative group learning and rated their work in groups as effect
ive. About half of the teachers reported problems with the monitoring of th
e cooperative groups. Observations showed the time-on-task levels of the pu
pils working in groups to be high, but effective learning and cooperation n
ot to be promoted. The teachers devoted little time to the teaching of grou
pwork skills. In general, the implementation of cooperative grouping was fo
und to lack the features recommended in the literature for effective cooper
ative learning.