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Lexile® Tracking Document Explained

The Lexile Framework

The Lexile® Framework for Reading is a scientific approach that places both the reader and text on the same developmental scale. The Lexile Analyzer® uses an algorithm to evaluate the text complexity of books, articles and other materials.

The Lexile Analyzer measures the complexity of the 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 the 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. Generally, longer sentences and words of lower frequency lead to higher Lexile measures; shorter sentences and words of higher frequency lead to lower Lexile measures. Texts such as lists, poetry and song lyrics are not analysed because they lack conventional punctuation.

Pupils and parents should look for reading materials with a reading comprehension “sweet spot” of 100L below to 50L above their Lexile measure. Reading materials in this range will provide an ideal level of challenge while maintaining comprehension.