This article explores influences on the development of collaborative learning practices in schools. Evidence from three cases in three countries is detailed and analyzed, using a theoretical framework concerned with school curricula: aims and intended learning outcomes; syllabus, learning and teaching methods; and assessment. In each of the three cases (England, Germany, and Lithuania), a review of national statutory requirements and nonstatutory guidelines is supported by evidence from teacher practice (in-depth case studies), which are then viewed through a comparative case-study method approach. The article highlights influences on practice, and draws conclusions about developing effective future policy and practices.