Lexile Framework for Reading

The Lexile® Framework for Reading is a scientific approach for measuring both reading ability and text complexity. Reading ability is conceptualized as a latent trait that influences a reader’s chance of success in comprehending professionally edited text and text complexity is a quantitative feature that represents the difficulty of a text.

There are two kinds of Lexile measures:
  • Lexile reading measure. Students receive a Lexile reading measure as a score from a reading test.
  • Lexile text measure. Books and other texts receive a Lexile text measure from the Lexile Text Analyzer.

When used together, these measures can help match a reader with reading material that is at an appropriate difficulty, or help give an idea of how well a reader will comprehend a text. Lexile measures are expressed as numeric measures followed by an “L” (for example, 850L), and are placed on the Lexile scale, ranging from below 0L for beginning readers and beginning reader materials to above 2000L for advanced readers and materials. Knowing the Lexile measures of both a reader and a text helps to forecast how well a reader will comprehend the text.

The Lexile reading measure can also be used to monitor a reader’s growth in reading ability over time. When a Lexile text measure matches or is in the range of a Lexile reading measure, this is called a targeted reading experience. The reader will encounter some level of difficulty with the text, but not enough to get frustrated. This is the best way to grow as a reader – reading text that’s not too hard but not too easy.

You can find detailed information in Lexile Framework for Reading Development and Validity Evidence.

Lexile Measures and Scale

A Lexile measure is the numeric representation of a reader’s ability or a text’s difficulty, both followed by an “L” (for Lexile measure). The Lexile scale is a developmental scale ranging from Beginning Reading measures (measures below 0L on the Lexile scale denoted by a BR prefix to the measure, e.g. BR100L) to above 1600L for advanced text and abilities. All Lexile Framework for Reading products, tools and services rely on the Lexile measure and scale to identify the Lexile levels of both the reader and text.

About the Lexile Text Analyzer

The Lexile Text Analyzer is a tool powered by the software developed by MetaMetrics that evaluates various characteristics of a text to determine its complexity. Lexile text measures are reported on the Lexile scale, so they can be compared to student Lexile reading measures, which are also reported on the Lexile scale. MetaMetrics recommends that readers select text with Lexile text measures within their Lexile reading range (i.e., +50L to -100L of their Lexile reading measure) for optimal challenge. However, texts above and below their Lexile reading range may be appropriate for specific reading conditions and purposes.

Before submitting any text to the Lexile Analyzer, the electronic files should be edited according to the established guidelines described in the Lexile Text Analyzer Text Preparation Guide. These guidelines include the removal of all incomplete sentences, chapter titles, paragraph headings, and running of a spell check. The text is then submitted to the Text Analyzer that examines the lengths of the sentences and the frequencies of the words for upper-level texts and the nine early-reader variables for lower-level texts. You can find detailed information about the Text Analyzer and the variables used to determine a text’s Lexile text measure in Lexile Framework for Reading Development and Validity Evidence. The Text Analyzer first examines the text features of a piece of text and attempts to determine if the text is written for early readers (early reader texts) or for more advanced readers (upper-level texts). Based on the examination results, the Text Analyzer applies the most appropriate word and sentence/discourse variables to the measurement process. The Text Analyzer then reports a Lexile text measure for the text. If the measure of the text is 650L or below, the four Early Reading Indicators are also reported.

Early Reading Indicators

Early Reading Indicators are additional pieces of information provided for texts 650L and below, that communicate the extent to which the nine variables used by the Text Analyzer to measure early reading texts are represented in the specific text. The nine variables have been grouped into four indicators:

  • Structure Indicator or "Patterns": Easier texts have more repeated words and phrases. Harder texts have fewer repeating words and phrases.

  • Semantic Indicator or "Vocabulary": Easier texts have more common, familiar, and concrete words. Harder texts have more rare, unfamiliar, and abstract words.

  • Decoding Indicator or "Decoding": Easier texts have words with fewer syllables and simpler sounds (e.g., “net” and “shop”). Harder texts have words with more syllables and more complex sounds (e.g., “balloon” and “ceremony”).

  • Syntactic Indicator "Sentences": Easier texts have shorter sentences and more words that overlap between sentences. Harder texts have longer sentences and fewer words that overlap between sentences.

Additional information on this topic can be found here.