The website of the Lexile Framework for Reading allows users to search a database containing many books with their Lexile measures. Lexile is a trademarked name for the measure of a student's ability or a book's suitability for students with a certain level of ability.
Appropriate reading choices for students range in Lexile from about 100 below a student's individual Lexile measure to 50 above. This range is designed to afford readers overall comprehension of a book but also provide some challenge in order to improve reading skills. Books' Lexile levels are determined by software analysis of their text complexity. Educational research company MetaMetrics developed Lexile measures after receiving a grant in 1984.