The Utility of CBM Written Language Indices: An Investigation of Production-Dependent, Production-Independent, and Accurate-Production Scores

This study examined the utility of three categories of CBM written language indices including production-dependent indices (Total Words Written, Words Spelled Correctly, and Correct Writing Sequences), production-independent indices (Percentage of Words Spelled Correctly and Percentage of Correct Writing Sequences), and an accurate-production indicator (Correct Minus Incorrect Writing Sequences) and was designed to answer three research questions. First, how do these categories of CBM written language scores relate to criterion measures, thus providing evidence for their valid use in assessing written language? Second, how do the three categories of CBM written language scores compare to one another across grade levels? Finally, are there gender differences in CBM writing scores? Predictions were tested using a sample of 203 second-, fourth-, and sixth-grade students from an Illinois school district. Results indicated grade level differences in how measures of written language related to students' scores on a published standardized achievement test, their Language Arts grade, and an analytic rating. Specifically, with older students, the production-independent and accurate-production measures were more related to standardized achievement scores, an analytic rating, and classroom grades than measures of writing fluency. Implications were made regarding the appropriateness of using each type of CBM written language index for different age levels, gender, and assessment purposes.