An Examination of Variability as a Function of Passage Variance in CBM Progress Monitoring

Abstract. This study examined the effects of controlling the level of difficulty on the sensitivity of repeated curriculum-based measurement (CBM). Participants included 99 students in Grades 2 through 5 who were administered CBM reading passage probes twice weekly over an 11-week period. Two sets of CBM reading progress monitoring materials were compared: (a) grade level material that was controlled for difficulty, and (b) uncontrolled randomly selected material from graded readers. Students ’ rate of progress in each progress monitoring series was summarized for slope, standard error of estimate, and standard error of slope. Re-sults suggested that controlled reading passages significantly reduced measure-ment error as compared to uncontrolled reading passages, leading to increased sensitivity and reliability of measurement. monitor student responsiveness to instruction over time in a formative manner. When used to index student progress in a formative manner, CBM has shown to b