What Are Lexile Measures?

 

The Lexile Framework® for Reading is a scientific approach to reading that places both readers and texts on the same measurement scale. Nearly half of all U.S. students receive Lexile measures from national, state, and local assessments.

 

Lexile measures are represented by a number followed by an “L” (such as “800L”) and range from below 150L for beginning readers and texts to 1600L or higher for advanced readers and certain texts. With Lexile measures, you can:

 

• Find “just right” books for independent reading
• Enhance instructional planning of challenging texts for all students
• Create small groups for differentiated instruction
• Communicate with students and parents/guardians regarding reading progress
• Set goals and monitor reading growth over years

Matching readers with texts on the Lexile Scale 

 

A Lexile reader measure describes a student’s reading ability. Connecting students with books within their independent Lexile range – often considered to be 100L below to 50L above their reported Lexile measure – provides an appropriate level of reading challenge.

 

A Lexile text measure indicates how challenging a text is to comprehend. Today, over 100 million books, articles, and websites have Lexile text measures.

Connecting students with appropriate challenge and support

 

Knowing the Lexile measure of a text and the Lexile measure of a student’s reading ability can identify an appropriate level of reading materials challenge for a student. Notwithstanding this, nothing can substitute for the expertise of an educator and his or her knowledge of each student. 

 

Reading comprehension is influenced by a number of factors:

 

Consequently, the Lexile level of a student and/or text alone or in conjunction will not be the only criteria for assigning reading materials to students or in choosing texts for instruction.

Lexile measures are based on the relationship between two well-established predictors of how difficult a text is to comprehend: semantic difficulty and syntactic complexity. The Lexile equation takes into account both the measurement of word frequency and sentence length, resulting in a measure of reading difficulty expressed as a Lexile. In the Lexile system:

• Semantic difficulty is measured using the mean log word frequency, which is the logarithm of the number of times a word appears for every 5 million words of text from a corpus of nearly 600 million words.
• Syntactic difficulty is a measure of the length of the sentences in a passage. Longer sentences are likely to contain more clauses, thereby communicating not only more information and ideas but also a more complex interrelationship between them.
• Short-term memory plays a role. Researchers speculate that longer sentences require the reader briefly to retain more information in her or his short-term memory. Nevertheless, students may refer to the article while answering the questions pertaining to it and reread it as needed.
• Schema building: Over time, students will access and synthesize a large amount of  information that will improve their ability to understand complex text.