It has been suggested that in order to truly understand student achievement, data must be collected with an assessment tool that includes a measure of performance, is psychometrically sound, and is consistent with cognitive psychology. Curriculum-based assessment for instructional design (CBA-ID) is presented as an assessment model that addresses those three criteria. The current article expands the literature on behavioral and psychometric components of CBA-ID by asking if age is a predictor of CBA-ID acquisition rate data, which allowed for a comparison between CBA-ID and memory research. The acquisition rates of 91 first-, third-, and fifth-grade students were obtained and correlated with their respective ages. Age was found to be a signficant predictor of acqusition rates for the total sample and for students in grades 1 and 3, but not for students in grade 5. A comparison of corrected coefficients suggested qualitative differences between younger and older children, which was consistent with results of previous memory research, thus supporting the consistency of CBA-ID with research from cogntive psychology.