AN EXPERIMENTAL COMPARISON OF ITEM SAMPLING AND EXAMINEE SAMPLING FOR ESTIMATING TEST NORMS

Abstract

An empirical comparison of the accuracy of item sampling and examinee sampling in estimating norm statistics. Item samples were composed of 3, 6, or 12 items selected from a total test of 50 multiple‐choice vocabulary questions. Overall, the study findings provided empirical evidence that item sampling is approximately as effective as examinee sampling for estimating the population mean and standard deviation. Contradictory trends occurred for lower ability and higher ability student populations in accuracy of estimated means and standard deviations when the number of items administered increased from 3 to 6 to 12. The findings from this study indicate that the variation of sequences of items occurring in item sampling need not have a significant affect on test performance.