Lexile Reading and Text Measures

The Lexile Framework for Reading features two measures:
  • The Lexile reading measure represents how well a student reads and comprehends text written in English. Students receive a Lexile reading measure after taking an English reading comprehension test.
  • The Lexile text measure represents the reading challenge of a piece of text. The Lexile® Text Analyzer, a software application developed by MetaMetrics, analyzes features of the text to determine its Lexile text measure.
Both measures are reported on the same developmental scale, the Lexile scale.

Lexile Reading Measures

When students take a reading comprehension test, their result is reported as a Lexile reading measure. MetaMetrics has developed a bank of test items that assess reading comprehension from early grades through high school. These items are used to develop reading tests for partners and to link the Lexile Framework for Reading with pre-existing reading tests. As a result, student scores can be reported as Lexile reading measures and used to monitor reading growth, forecast comprehension of text, and select appropriate reading materials. Lexile reading measures are expressed as numeric measures followed by an “L” (for example, 850L) and are placed on the Lexile scale, ranging from below 0L (e.g., BR50L) for beginning readers to above 1600L for advanced readers.

The Lexile reading item bank contains over 10,000 reading comprehension items developed since 1986. The passages used are either excerpted from authentic text or developed by professional writers commissioned by MetaMetrics. Passages include material that students will likely encounter both in and out of the classroom. Sources include textbooks, literature, and periodicals from a variety of interest areas and by authors of different backgrounds. Passages authored or commissioned by MetaMetrics are created to model real-world reading materials.

Items used to assess the reading ability of early readers include picture items, picture/word audio-enhanced items, one-sentence items, and two-sentence items. These items are designed using Lexile-appropriate vocabulary, sight words, images, and other text characteristics typically associated with early reading.

You can find detailed information about the types of reading items developed by MetaMetrics in Lexile Framework for Reading Development and Validity Evidence.

Lexile Text Measures

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. Lexile text measures are expressed as numeric measures followed by an “L” (for example, 650L), and are placed on the Lexile scale, ranging from below 0L (e.g., BR120L) for beginning reader text to above 1600L for advanced text. For the optimal challenge, 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). However, texts above and below their Lexile reading range may be appropriate for specific reading conditions and purposes.

Prior to submitting any text to the Lexile Analyzer, the electronic files should be edited according to the established guidelines as described in the Lexile Text Analyzer Text Preparation Guide. These guidelines include the removal of all incomplete sentences, chapter titles, and paragraph headings; and the running of a spell check. The text is then submitted to the Text Analyzer, which examines the lengths of the sentences and the frequencies of the words for upper-level texts and 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.

When determining the Lexile text measure of upper-level texts, or those typically designed for readers in grade 2 and above, the Text Analyzer uses sentence length and word frequency variables to determine the Lexile text measure.

When determining the Lexile text measure of early reader texts, or those typically designed with characteristics to help support students as they are learning to read, the Text Analyzer uses nine variables to determine the Lexile text measure. In addition to sentence length and word frequency variables, the Text Analyzer incorporates decoding, patterning, and structure variables and more word/vocabulary variables.

If the measure of the text is 650L or below, the four Early Reading Indicators are also reported. The four indicators are also shown on the book information page in Find a Book for early reading books on the You can see examples in Find a Book on the Hub.

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 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.

Partners can license the Lexile Text Analyzer API to measure text. See About the Lexile Text Analyzer API for more information.