Outline of the Talk. The initial problem ? preventing social exclusionDistributed expertise and professional practicesInter-professional workingRelational agency and common knowledge. The Studies ? all shaped by Vygotskian frameworks . Two DfES/DCSF studies of inter-professional practices with children and familiesTLRP study of Learning in and for Interagency WorkingESRC study of practices at the boundaries of schoolsCurrent CWDC study of remodelled social workStarting two studies of strategic practices to support inter-professional work.