The IRT Procedure (Experimental)

FREQ Statement

FREQ variable ;

If one variable in your data set represents the frequency of occurrence for the other values in the observation, specify the variable’s name in a FREQ statement. PROC IRT then treats the data set as if each observation appears $n_ i$ times, where $n_ i$ is the value of the FREQ variable for observation i. Only the integer portion of the value is used. If the value of the FREQ variable is less than 1 or is missing, that observation is not included in the analysis. The total number of observations is considered to be the sum of the FREQ values.