Defining Text Complexity


"Quite one of those great waves off of Hawaii
that comes along every 40 years."
—Roy Romer

The Common Core State Standards Initiative places a strong emphasis on the role of text complexity in evaluating student readiness for college and careers. To follow are the Common Core Standards' three equally important components of text complexity, along with how Lexile measures can support them.


Qualitative dimensions of text complexity, such as levels of meaning, structure, language conventionality and clarity, and knowledge demands. Lexile codes provide more information about a book's characteristics, such as its developmental appropriateness, reading difficulty, and common or intended usage.

Quantitative measures of text complexity, such as word frequency and sentence length, which are typically measured by computer software. The Lexile® Analyzer measures text demand based on these two widely adopted variables.

Reader and task considerations, such as students' knowledge, motivation and interests. The free "Find a Book" search helps readers build custom book lists based on their ability (Lexile measure) and personal interests or school assignments.

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*Roy Romer has served as the Governor of Colorado, the Superintendent of Los Angeles Unified School District, and the first Chair of the National Education Goals Panel (in 1991).