Adopting a new series of tests can raise student test scores. Scores can also be inflated by ensuring certain students do not take specific tests or by not counting some scores. Dramatic rises in standardized scores are likely to be accompanied by skepticism. (MD)

The Rasch model was used to compare the grade equivalent scores which students of equal ability would have obtained, had they taken different levels of the Iowa Tests of Basic Skills (ITBS). Raw scores on items common to levels 9-14 of the ITBS (vocabulary subtest) were obtained from 6,000 students in Dallas, Texas. Rasch scales were used to…