This volume brings together a collection of chapters outlining the principles and processes of action research and providing case studies of practitioner action research completed by teachers in the ELICOS (English Language Intensive Courses for Overseas Students) sector in Australia. The Action Research in ELICOS programme in which the teachers participated was an innovative collaboration between English Australia, the professional body for ELICOS, and Cambridge English Language Assessment commencing in 2010 and continuing to the present. An introductory chapter describes the initiation of the programme and the professional model adopted to support and facilitate the teachers' research, while a concluding chapter considers the impact of the programme on the teachers and on the ELICOS sector more generally. Case studies by the teachers present the action research processes they undertook to research receptive and productive skills and assessment of these skills in their classrooms.