Conversation Analysis (CA) is the theoretical and methodological framework that inspires the contributions to this edited volume. CA is an approach and methodology in the social sciences that is rooted in ethnomethodology (EM) and aims to describe, analyze, and understand interaction as “a basic and constitutive feature of human social life”. This volume uses ethnomethodological conversation analysis (EMCA) to: (1) develop a unified, emic (or participant-relevant) account of how members do classroom interaction in various contexts; and (2) explore how second language acquisition (SLA) research that uses CA methods (CA-SLA) can potentially be used to develop new, empirically grounded pedagogical implications by and for a broad range of language teaching professionals. Most importantly, the present volume seeks to break new ground by trying to promote an ongoing exchange of ideas among the many different stakeholders in the community of language learning/teaching professionals who constitute our intended audience. It is also proposed that future interventionist CA-based research on classroom interaction would be enriched by the adoption of an ethnographic diffusion of innovations perspective on educational change; specifically, it is argued that all stakeholders need to develop a consumers’ understanding of how to package insights from CA as useful resources for on-going curricular innovation.