Curriculum-based measurement of oral reading: Passage equivalence and probe-set development

Curriculum-based measurement of reading (CBM-R) is used to estimate oral reading fluency. Unlike many traditional published tests, CBM-R materials are often comprised of 20 to 30 alternate forms/passages. Historically, CBM-R assessment materials were sampled from curricular materials. Recent research has documented the potentially deleterious effects of poorly controlled alternate forms on CBM-R outcomes. The purpose of this study was to examine alternate procedures for the selection of passages that comprise CBM-R passage-sets. The study examined four procedures for the evaluation and selection of passages, including random sampling, Spache readability formula, mean level of performance evaluation, and Euclidean Distance evaluation. The latter two procedures relied on field testing and evaluation of student performance. Each of eighty-eight students in second- and third-grade were administered 50 CBM-R passages. Generalizability and dependability studies were used to examine students' performance on these passages and evaluate CBM-R passage selection procedures. Results provide support for the use of field testing methods (i.e., calculating performance means and Euclidean Distances) for passage selection. Implications are discussed for future research and practice.