Measures of Text Difficulty: Testing their Predictive Value for Grade Levels and Student Performance

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This study assessed the capabilities of six text difficulty metrics to predict reference measures of text difficulty. The six metrics were as follows: Lexile (MetaMetrics), ATOS (Renaissance), Degrees of Reading Power: DRP Analyzer (Questar Assessment, Inc.), REAP (Carnegie Mellon University), SourceRater (Educational Testing Service), and the Pearson Reading Maturity Metric (Pearson Knowledge Technologies). Additionally, the study included a seventh metric (Coh-Metrix, University of Memphis) that provides multiple indices of text difficulty. All of the metrics were found to be reliably, and often highly, correlated with grade level and student performance-based measures of text difficulty across a variety of text sets, and across a variety of reference measures.

AUTHORS: Jessica Nelson, Charles Perfetti, David Liben, and Meredith Liben.

The full report is available online.

Results informed the supplement to Appendix A of the Common Core State Standards for English Language Arts and Literacy that is available online.

The citation: Nelson, J., Perfetti, C., Liben, D., & Liben, M. (2012). Measures of text difficulty: Testing their predictive value for grade levels and student performance. Technical Report to the Gates Foundation.

Publication Date:

Updated: 02/01/2012

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