This appendix provides norms for the indices described in Chapters 4 and 5. To create these norms, we analyzed a subset of a large corpus of texts created by the Touchstone Applied Science Associates (TASA), Inc. The total TASA corpus includes 9 genres consisting of 119,627 paragraphs taken from 37,651 samples. The norms are provided for the three largest domains represented in TASA: language arts, social studies, and science texts. To do so, we randomly chose 100 passages from each of the 3 genres and each of 13 grade levels, for a total of 3,900 passages.

Grade level in the TASA corpus is indexed by the Degrees of Reading Power (DRP; Koslin et al., 1987), which is a readability measure that includes word- and sentence-level characteristics. As can be observed in the table, DRP is highly correlated with the Flesch Reading Ease and Flesch–Kincaid Grade Level measures of readability.

To simplify the data analysis and presentation, DRP levels were translated to their corresponding grade-level estimates and then collapsed according to the grade bands used within the Common Core State Standards: grades K to 1, 2 to 3, 4 to 5, 6 to 8, 9 to 10, and 11 and higher. Each grade level within each genre was represented by 100 passages. Because the Common Core grade bands include different numbers of grade levels per band (e.g., 2–3 includes two grades, 6–8 includes three grades), there are different numbers of passages represented for each grade band. The average DRP values as well as the range of DRP values for each grade band are provided in the Table B.1.