Patsy M. Lightbown is Distinguished Professor Emerita at Concordia University in Montreal and Past President of the American Association for Applied Linguistics. Her research focuses on how instruction and feedback affect second-language acquisition in classrooms where the emphasis is on "communicative" or "content-based" language teaching. The contexts for her work have included elementary schools in Canada and, more recently, dual-language bilingual classes in the U.S. Nina Spada is Professor of Applied Linguistics at the Modern Language Centre, Ontario Institute for Studies in Education at the University of Toronto, Canada. Her main areas of professional interest are second language acquisition, classroom research in L2 teaching and learning, and English as a Second Language.