This thesis offers an in-depth analysis of conceptual, methodological, and policy issues in the implementation of children's participation rights. The way in which children's participation is understood and operationalised within and across services affecting children is a related area for study. The thesis explores the varied emphases given to children's participation rights (and multi-agency working) within and across play, educational, health, welfare and out-ofschool services; and it examines and discusses conceptual, policy and practice issues in the implementation of children's participation rights within and across these services. The example of the development of an out-of-school centre known as "A Space" is then used to provide a detailed analysis of the progress and process of participative and multi-agency working. Both the A Space exemplar and the wider public policy context within which it is located are viewed as forms of 'data' -and it is these two forms of data which are considered together. The thesis suggests that whilst it seems possible to make some progress towards implementing some elements of children's participation considerable barriers exist. These barriers include the tensions which exist between the interests of children and of adults; the constraints of public policy agendas, socio-economic considerations, and the kinds of welfarist and developmentalist understandings of children and childhood which underpin the approaches of children's service agencies and the perspectives of the staff therein. It concludes that if the implementation of children's participation is to be anything more than a 'token' exercise then ways will need to be found to overcome these barriers.