MaryAnn Christison is Professor in the Department of Linguistics and the Urban Institute for Teacher Education at the University of Utah in Salt Lake City, Utah, where she teaches courses at both graduate and undergraduate levels. She is a co-author of three volumes in the series What English Language Teachers Need to Know, and serves on the Board of Trustees of TIRF. Donna Christian is Senior Fellow with the Center for Applied Linguistics in Washington, DC. Her interests focus on language diversity in education, particularly dual language education, second language teaching, and policy. She is an Associate Editor of the journal Language for Language and Public Policy articles and serves on the Board of Trustees of TIRF. Patricia A. Duff is Professor of Language and Literacy Education at the University of British Columbia, where she coordinates and teaches in the program in Teaching English as a Second Language. Her scholarly interests include language socialization across bilingual and multilingual settings and issues in the teaching and learning of languages. She is a past trustee of TIRF. Nina Spada is Professor in the Language and Literacies Education program at OISE, University of Toronto, where she teaches courses in second language (L2) acquisition, research methods, and the role of instruction in L2 learning. Her classroom research focuses on the contributions of form-based and meaning-based instruction to L2 learning.