An equating study was conducted on the Certifying Examination for Primary Care Physician's Assistants to compare the ability of current examinees with the standardization group and to determine if current test items are more difficult than previous items. Using 46 common items from the multiple choice section, the 1978 exam was equated to the 1976 version by four methods: Rasch, linear raw, linear short-cut, and traditional item statistics. Raw scores for the current examination, scored traditionally and equated to the 1976 test by the four methods, reflect the fact that current examinees performed better on the 46 common items than the reference examinees. Only the Rasch model however, was able to confirm that items on the current test were more difficult. This model can be used to determine whether or not examination standards should be raised as training programs improve. (CP)