This user-friendly, practical book is the first guide to single-case design written specifically for practitioners using Response To Intervention (RTI) models in schools. It provides essential skills for analyzing and presenting data to support valid educational decision making. Step-by-step explanations and many illustrative examples render complex concepts accessible and applicable to day-to-day work with elementary and secondary students. In a large-size format with lay-flat binding for ease of photocopying, the book includes reproducible graphs and forms. Two hands-on appendices offer clear instructions for summarizing and analyzing data using computer spreadsheets.