Participatory Action Research (PAR) approaches and methods have seen an explosion of recent interest in the social and environmental sciences. PAR involves collaborative research, education and action which is oriented towards social change, representing a major epistemological challenge to mainstream research traditions. It has recently been the subject of heated critique and debate and rapid theoretical and methodological development. This book captures these developments, exploring the justification, theorization, practice and implications of PAR. It offers a critical introduction to understanding and working with PAR in different social, spatial and institutional contexts. The authors engage with PAR's radical potential, while maintaining a critical awareness of its challenges and dangers.The book is divided into three parts. The first part explores the intellectual, ethical and pragmatic contexts of PAR; the development and diversity of approaches to PAR; recent post structuralist perspectives on PAR as a form of power; the ethic of participation; and issues of safety and well-being. Part two is a critical exploration of the politics, places and practices of PAR. Contributors draw on diverse research experiences with differently situated groups and issues including environmentally sustainable practices, family livelihoods, sexual health, gendered experiences of employment, and specific communities such as people with disabilities, migrant groups, and young people. The principles, dilemmas and strategies associated with participatory approaches and methods including diagramming, cartographies, art, theatre, photovoice, video and geographical information systems are also discussed. Part three reflects on how effective PAR is, including the analysis of its products and processes, participatory learning, representation and dissemination, institutional benefits and challenges, and working between research, action, activism and change. The authors find that a spatial perspective and an attention to scale offer helpful means of negotiating the potentials and paradoxes of PAR. This approach responds to critiques of PAR by highlighting how the spatial politics of practicing participation can be mobilized to create more effective and just research processes and outcomes. The book adds significant weight to the recent critical reappraisal of PAR, suggesting why, when, where and how we might take forward PAR's commitment to enabling collaborative social transformation. It will be particularly useful to researchers and students of Human Geography, Development Studies and Sociology.