Different forms of any test may vary somewhat in difficulty. Because of the differences in difficulty between different forms of the PCAT, the same raw scores on different forms are not necessarily equivalent. Using the statistical process of equating, it is possible to express scores in comparable terms across different forms of the test. Scaled scores are used for this purpose. The scale used for the PCAT ranges from 200 to 600, with a median of 400 (i.e., a scaled score of 400 corresponds to the 50th percentile).
In addition to scaled scores, your Score Report will list five subtest percentile scores and a Composite percentile score. The percentile score shown on your Score Report indicates the percentage of PCAT examinees that made up the norm group--all first-time examinees who took the test between October 1998 and March 2003--with scaled scores equal to or lower than yours. For example, an examinee who earns a Composite percentile score of 70 scored equal to or higher than 70% of the examinees from the norm group on the test as a whole."