The Common Core State Standards Initiative has placed a stronger emphasis on the role of text complexity in determining student readiness for college and careers. Both the Common Core Standards and Race to the Top promote standards that ensure students' abilities to read and comprehend texts of steadily increasing complexity—the most important factor of being college and career ready—as they progress through school. By the time they complete the core curriculum, students must be able to read independently the kinds of texts commonly found in postsecondary pursuits.

Common Core's Appendix A identifies The Lexile Framework for Reading as one option for measuring text complexity. The Lexile Framework differs from the other readability formulas in that it measures both text complexity and reading ability on the same developmental scale, enabling students' comprehension rates to be forecasted for specific reading materials and to monitor their progress toward college and career text demands.

More than 150 publishers already offer Lexile measures for their reading materials. The Lexile Titles Database is comprised of tens of thousands of fiction and nonfiction titles with Lexile measures, and hundreds of millions of articles also have been assigned a Lexile measure. Click here to use "Find a Book" to search for titles by Lexile measure and subject categories.

Getting Lexile Measures

MetaMetrics assigns Lexile measures using the Lexile® Analyzer, a software program designed to evaluate the reading demand, or readability, of books and test items. The Lexile Analyzer measures text by breaking down the entire piece and studying its characteristics, such as sentence length and word frequency, which represent the syntactic and semantic challenges that a text presents to a reader. The outcome is the text complexity, expressed as a Lexile measure, along with information on the word count, mean sentence length and mean log frequency. Some books are also assigned a Lexile code, which is a two letter designation that appears before the Lexile measure (for example, AD580L) to provide more information about the book's developmental appropriateness, reading difficulty, and common or intended usage.

Generally, longer sentence lengths and words of lower frequency lead to higher Lexile measures; shorter sentence lengths and words of higher frequency lead to lower Lexile measures. Texts such as lists, recipes, poetry and song lyrics are not analyzed because they lack conventional punctuation.

For more information on text measurement and the value of assigning certified Lexile measures to your materials, visit our publishers section.