In the 19th century, educators discovered that books of a simpler style were better for teaching students to read. They began separating students into classes and grading books for different classes. Early in the 20th century, they discovered many adults had limited reading ability. 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. That story was briefly covered in a companion book, Smart Language: Readers, Reading, and the Grading of Text. This book presents ten of the original landmark studies of of these educational pioneers. As with all scientific efforts, they built on one another. Reading them in context highlights their special place the story of our remarkable language.