A Lexile range is a score (displayed as a 150-point range) resulting from a correlation between RIT score and the Lexile scale that helps identify reading material that is at an appropriate difficulty level for an individual student. The 150-point Lexile range is included on Individual Student Progress Reports. It allows educators and parents to find books, periodicals, and other reading material that should stimulate a student to new learning while rewarding their current reading abilities. 

A lexile measures syntactic complexity – the number of words per sentence. We know that longer sentences are more complex and require more short-term memory to process. A Lexile also measures semantic difficulty – a measure of vocabulary. This measure looks at the frequency of words in a text compared to a body of over 400 million words. This is the largest repository of text in the world and is quickly approaching 500 million words. 

It is very important for parent to keep in mind that Lexile does not evaluate genre, theme, content, or interest. Even though a student might be able to read books at a certain Lexile, the content or theme of the text may not be appropriate for that particular student because of his or her age or development level. Also, a student may be able to read more difficult content if it is an area of interest for that child since he or she may already be familiar with some of the vocabulary necessary to comprehend the text.

The Lexile database currently includes over 135,000 books. You can access the Lexile website at www.lexile.com. You can search titles (both Spanish and English) at the website free of charge. The regular search feature allows you to search by title, author, ISBN, subject, or Lexile range. By using the detailed search on the same page, you can also search by theme, interest, or content area. Other features of the website include frequently asked questions, the Lexile Times Newsletter, a parent link, and a reading calendar. Check it out!