This book is a comprehensive introduction to the topic of assessing students who use two or more languages in their daily life. The book provides foundational information for assessing multilingual learners (ML) in schools, with an emphasis on school language and content. Major assessment ideas are viewed through a framework called PUMI (Purpose, Use, Method, and Instrument) to help readers focus on important assessment principles, leading to better quality assessments for MLs. This is a substantially revised and updated 2nd edition of The Assessment of Emergent Bilinguals. Updates in this edition include a greater focus on multilingual assessment and assessment in language contexts in addition to English/Spanish. This edition addresses both the current politics of multilingual assessment and recent theoretical developments, including an expanded exploration of translanguaging in assessment contexts. This edition aims to be more practical than the first edition, with more examples of assessments and rubrics, and a greater emphasis on using assessment results in formative ways.