https://doi.org/10.1177/0002764218775782 American Behavioral Scientist 1–20 © 2018 SAGE Publications Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/0002764218775782 journals.sagepub.com/home/abs Article Ethical and Methodological Issues in Large Qualitative Participatory Studies Naomi Hossain 1 and Patta Scott-Villiers 1 Abstract Participatory research studies utilizing qualitative data drawn from large, diverse samples appear increasingly common in the social sciences, particularly in international development. This reflects demand for participatory approaches to researching human well-being at scale, comparative research on globalization and development, and breadth and scale in evidence-based policy making. “Big Qual” studies in international development increasingly combine qualitative with participatory methods and incorporate action research, oral histories, case studies, and visual methods. Apart from their scale (more sites and research participants than conventional “face-to-face” research) and diversity of contexts, these studies broadly share a focus on application, and an epistemological and ideological commitment to hearing and amplifying the voices of research participants and contributing to positive change in their lives. Some ethical challenges of Big Qual research—for example, reuse, storage, and sharing of third party data—have been thoroughly debated. Less is known of how complexities across time, space, and culture may shape researcher relations in large-scale participatory research, biasing results against context-specificity and meaningful local political analysis. Drawing on almost a decade’s experience with large participatory research, this article explores why and how scale, encompassing a complex network of institutions, relationships, contexts, and cultures, affects the ethics of these studies. We propose that Bradbury and Reason’s (2001) five criteria for judging the value and contribution of social inquiry are helpful: (a) the quality of relationships built, (b) the usefulness of the research, (c) its trustworthiness, (d) its relevance to vital issues of human society, and (e) its enduring consequence. Drawn from an action research tradition, these criteria constitute a comprehensive ethical framework particularly applicable to Big Qual participatory work in development studies. Through an empirical application of these criteria, the article highlights emerging ethical challenges facing applied social research in increasingly complex, multiscalar, and globalized contexts. 1 University of Sussex, Brighton, UK Corresponding Author: Naomi Hossain, Institute of Development Studies, University of Sussex, Library Road, Brighton BN19RE, UK. Email: n.hossain@ids.ac.uk 775782ABS XX X 10.1177/0002764218775782American Behavioral ScientistHossain and Scott-Villiers research-article 2018