Jill Korey O'Sullivan has worked in the fields of English as a second language and literacy acquisition as a teacher, writer, and editor. She has taught and developed materials for students of a broad range of levels and in a variety of educational settings, including kindergarten, middle school, community college, and adult education programs. Ms. Korey O'Sullivan holds a Masters Degree in Education from Harvard University. Dr. Joan Kang Shin is an Associate Professor of Education at George Mason University and the Academic Program Coordinator of the Teaching Culturally & Linguistically Diverse & Exceptional Learners (TCLDEL) program. Dr. Shin specializes in teaching ESL/EFL to young learners and teenagers and has provided professional development programs and workshops to EFL teachers in over 100 countries around the world. She is a Series Editor of National Geographic Learning's young learner programs Welcome to Our World, Our World, and Explore Our World, as well as the teen program Impact, and an author of the professional development title Teaching Young Learners English.