ARDMS uses a criterion-referenced methodology for scoring all examinations. With this type of scoring methodology, there is no curve and candidates do not compete against each other. In constructing criterion-referenced examinations for ARDMS, the most important score is the cut-off score, which represents basic competency. A great deal of time is spent ensuring that the cut-off scores are derived fairly.
An analysis of the examination questions is produced using a variation of the Bookmark scoring method and other classical testing approaches. Approximately 15 percent of the test questions may appear as non-scored trial items. These items are used for future exam development and candidates will not know which are the trial questions.
ARDMS test results are reported as scaled scores, ranging from 300 to 700. A scaled score of 555 (cut-off score) is required to pass all ARDMS examinations. The scaled score is not a percentage point of correct answers, nor is it built on a "curve" where a certain percentage of scores would pass and a certain percentage would fail.
ARDMS examinations for the RDMS, RDCS, RVT, RPVI and RMSK credentials are constructed to assess the knowledge and skills involved in tasks performed by sonographers and vascular technologists. The psychometric basis for the validity of the examinations is developed from consideration of the universe of tasks performed by sonographers and vascular technologists. The examination does not consider, is not based upon, and should not be construed to be either a measurement of diagnostic assessment tasks as utilized by licensed physicians or an evaluation of the competency of a practicing physician using ultrasound for diagnosis.