Following Ellis's (2005) call for more social and process-oriented planning research, this study explores how learners approach collaborative planning tasks in the classroom as a locally contingent activity in situ. Drawing on ethnomethodology and conversation analysis, the present study focuses on a group planning stage that precedes the final task of delivering a presentation. Fine-grained analyses of the interaction reveal that group planning is essentially a nonlinear, social, and pragmatic activity wherein the students manage participant roles, resolve disputes and misunderstandings, and collectively work toward effective task completion. These findings highlight that, although the groups begin with the same task-as-workplan (Breen, 1987;Seedhouse, 2005), the students' concerns are driven by locally constructed goals and plans-in-process, and as they work toward a group consensus they are required to deal with a wide range of social and interactional contingencies. I n the field of second language acquisition (SLA), planning has long been treated as a task implementation variable that has an effect on the quantity and quality of second language (L2) oral production. The predominance of such product-based approaches instigated Ellis's (2005) call for more process-oriented research, and ever since, increasing work from various perspectives have documented what learners do while planning. Yet, systematic analyses on the real-time unfolding of planning are still limited (Ellis, 2009a), especially when it comes to collaborative planning carried out in many task-based classes. Greater methodological rigor is needed in how we characterize planning in relation to its social contexts of use, participant orientations, and evolving trajectories within sequences of interaction. Lee is an assistant professor of English Education at Ewha Womans University in Seoul, South Korea. Her research interests center on applying ethnomethodology and conversation analysis to studies on L2 pedagogy, classroom interaction, and pragmatics. Her recent work has appeared in Applied Linguistics, Journal of Pragmatics, and Social Semiotics.Alfred Rue Burch is currently a postdoctoral fellow in the Center for Languages and Intercultural Communications at Rice University. His interests include conversation analysis (CA), second language acquisition (SLA), and interactional competence, in particular focusing on how "traditional" SLA topics such as motivation and communication strategies can be explored and re-specified using CA.