Joan Kelly Hall is Professor of Applied Linguistics and Director of the Center for Research on English Language Learning and Teaching (CRELLT) at the Pennsylvania State University, USA. Her research centers on documenting the specialized interactional practices and actions of teaching-and-learning found in instructional settings. Her most recent book is Essentials of SLA for L2 Teachers: A Transdisciplinary Framework (2019, Routledge).

Stephen Daniel Looney is an Associate Teaching Professor in Applied Linguistics and Director of the International Teaching Assistant (ITA) Program in the Department of Applied Linguistics at the Pennsylvania State University, USA. His research analyzes teacher-student interaction in university STEM classrooms. He is coeditor of A Transdisciplinary Approach to International Teaching Assistants (Multilingual Matters, 2019) and has recent publications in Journal of Pragmatics and Linguistics and Education.