Clemans (1993) argued that the use of item response theory (IRT) to vertically scale Form E of the California Achievement Tests produces inappropriate results. In this response we show that (a) Cleman's analysis of school district data was incomplete, inconsistent, and did not follow good measurement practice; (b) the simulation he conducted was unfairly stacked against IRT, was unrealistic, and ignored other realistic published simulations that demonstrated the accuracy of IRT scaling procedures; (c) his "common sense" evaluations of student performance ignored basic facts about the measurement of student achievement; and (d) the concerns expressed in his article were irrelevant to the vast majority of uses of norm-referenced tests.