I wish I had this outstanding book when I was a bilingual teacher! Mahoney demystifies psychometric principles and practices with real-world classroom examples and provides a useful tool for teachers to make appropriate informed decisions about the development, use, and interpretation of formative and summative assessments with multilingual learners. * Wayne E. Wright, Purdue University, USA * This is one of the most important and influential textbooks about the assessment of children learning English as a second language in K-12 public schools to date. It is engaging, grounded in a useful analytical framework, and takes a critical stance on standardized testing with English learners. Kate Mahoney provides a student-friendly overview of psychometrics through an equity and social justice lens. In short, this book is stellar. * Mary Carol Combs, University of Arizona, USA * Kate Mahoneys invaluable and much-loved textbook has been widely adopted in teacher education programs because it offers a thorough, practical, and accessible introduction to the assessment of multilingual learners. Its expertly crafted guidance and innovative framework is essential for educators, as it provides the tools needed to make informed assessment decisions, while taking up a critical, timely approach and embracing students bilingual language practices. * Kate Menken, City University of New York (CUNY), USA *