Section 1: Introduction. Chapter 1. An Overview of English Language Proficiency Assessments for Young Learners by Mikyung Kim Wolf & Yuko Goto Butler. Section 2: Theoretical Basis and Assessment Frameworks. Chapter 2. Theoretical and Developmental Issues to Consider in the Assessment of Young Learners’ English Language Proficiency by Alison Bailey. Chapter 3. Designing TOEFL® Primary TM Tests by Yeonsuk Cho, Mitch Ginsburgh, Rick Morgan, Brad Moulder, Xiaoming Xi, & Maurice Cogan Hauck. Chapter 4 TOEFL Junior® Design Framework by Youngsoon So, Mikyung Kim Wolf, Maurice Cogan Hauck, Pamela Mollaun, Paul Rybinski, Daniel Tumposky, & Lin Wang. Chapter 5. Designing Task Types for English Language Proficiency Assessments for K-12 English Learners in the U.S. by Maurice Cogan Hauck, Emilie Pooler, Mikyung Kim Wolf, Alexis Lopez & David Anderson. Section 3: Empirical Studies for Validity Evidence. Chapter 6. A Field Test Study for the TOEFL® Primary TM Reading and Listening Tests by Jiyun Zu, Bradley Moulder, & Rick Morgan. Chapter 7. Strategies Used by Young English Learners in an Assessment Context by Lin Gu & Youngsoon So. Chapter 8. Using the Common European Framework of Reference to Facilitate Score Interpretations for Young Learners’ English Language Proficiency Assessments by Spiros Papageorgiou & Patricia Baron. Chapter 9. Making a Validity Argument for Using the TOEFL Junior Standard Test as a Measure of Progress for Young English Language Learners by Lin Gu, J. R. Lockwood, & Donald E. Powers. Chapter 10. Comparing the Performance of Young English Language Learners and Native English Speakers on Speaking Assessment Tasks by Mikyung Kim Wolf, Alexis Lopez, Saerhim Oh, & Fred S. Tsutagawa. Section 4: Future Assessments and Innovations for Young Learners. Chapter 11. Considering Young Learners’ Characteristics in Developing a Diagnostic Assessment by Eunice Eunhee Jang, Megan Vincett, Edith van der Boom, Clarissa Lau, & Yehbeen Yang. Chapter 12. Computerized Dynamic Assessments for Young Language Learners by Matthew E. Poehner, Jie Zhang, & Xiaofei Lu. Chapter 13. Measuring 21st Century Reading Comprehension Through Scenario-Based Assessments by Jane Shore, Mikyung Kim Wolf, Tenaha O’Reilly, & John P. Sabatini. Section 5: Conclusion. Chapter 14. Challenges and Future Directions for Young Learners’ English Language Assessments and Validity Research by Yuko Goto Butler. Appendices.