Item-level and construct evaluation of early numeracy curriculum-based measures

Abstract

The present study examined the technical adequacy of curriculum-based measures (CBMs) of early numeracy. Six 1-min early mathematics tasks were administered to 137 kindergarten and first-grade students, along with an omnibus test of early mathematics. The CBM measures included Count Out Loud, Quantity Discrimination, Number Identification, Missing Number, Next Number, and Number Facts. Alpha and split-half reliabilities were assessed, and construct validity and criterion validity (both concurrent and predictive) were examined. In addition, an item analysis was conducted for each measure using classical test theory and item response theory approaches, specifically using a Rasch model. Results indicated that the measures produced moderately strong reliability coefficients, satisfactory item difficulty and discrimination, evidence to support both concurrent and predictive validity with the standardized early mathematics test, and the tasks appeared to be measuring the construct of early numeracy proficiency. © 2012 Hammill Institute on Disabilities.