The widely adopted Common Core State Standards (CCSS) call for raising the level of text complexity in textbooks and reading materials used by students across all grade levels in the United States; the authors of the English Language Arts component of the CCSS build their case for higher complexity in part upon a research base they say shows a…

Early in the 20th century, educators began looking for scientific methods for matching texts with readers. Some of the best minds in education dedicated themselves to this task, including Edward L. Thorndike, William S. Gray, Ralph Tyler, Edgar Dale, Irving Lorge, and Jeanne S. Chall. The purpose of this book is to bring students of reading into…