This trusted text and teacher resource is now in a revised and updated fifth edition, reflecting key advances in the science of reading. It covers the "whys," "whats," and "how-tos" of systematic reading assessment in grades K-8. The authors provide a roadmap and practical tools for evaluating students' strengths and needs in each component of reading, resulting in a seamless integration of assessment, evidence-based instruction, and intervention. Essential topics include evaluating the comprehension of beginning readers, assessing older struggling readers, supporting English learners, and preparing diagnostic reading reports. In a convenient large-size format, the book includes 30 reproducible and downloadable tools, plus an online-only appendix with an additional multipage assessment. New to This Edition Explicitly connects assessment guidelines to the science of reading. New chapter on morphology and significantly revised chapters on orthography and assessment of holistic reading. Aligns with the NAEP 2026 reading framework and definitions. Fully updated research, additional instructional resources, and two new assessments--Text Analysis Tool and Reading Engagement Scale.