Assigning Grade Levels to Textbooks: Is It Just Readability?
David F. Dufty, Arthur C. Graesser, Max M. Louwerse, Danielle S. McNamara · eScholarship (California Digital Library) · 2006
We evaluated the effectiveness of new indices of text cohesion to determine the appropriate human assigned grade level of a text.In particular, we investigated the efficacy of automated text indices produced by the online tool Coh-Metrix in predicting the grade level assigned by publishers to their own textbooks.To do this, we sampled 311 school textbooks from a large database, choosing roughly equal numbers of science, narrative, and social science texts.Publisher-assigned grade levels were found to be moderately predictable by traditional approaches such as the Flesch-Kincaid Grade Level.Prediction of grade level was significantly improved by the inclusion of cohesion indices obtained by Coh-Metrix.Implications for the improvement of textbook selection are discussed.