The main purpose of this study was to compare the validity and reliability of math within
different time administration. Recently, CBM is referred to as one of alternative methods within an
RTI model. In order to confirm the usefulness of CBM within an RTI model, however, it is
necessary to establish the validity and reliability of CBM measures. It is assumed that different time
administration result in difference in technical adequacy of CBM measures. For this reason, a wealth
of research has been conducted in U.S, but there are few studies on the topic in Korea. In this
study, descriptive statistics, correlation coefficients, and simple linear regression were used for
answering the research questions used. The results from this study show that CBM with 1 min
administration was better than CBM with 2 min administration. The implications and limitations of
this study are discussed.