The first few questions are of moderate difficulty. Each time an examinee answers a question, the computer re-estimates the examinee's ability. Then, based upon that estimate, the computer selects the next item that is expected to challenge the examinee. By using a 90 item adaptive test, we can achieve the same precision in examinee ability estimates as a 200 item non-adaptive written test. This makes the test less grueling.
Adaptive tests have another advantage over fixed form tests.
Examinees are not asked questions that are so far beyond their ability that they have to guess. This means there will be less error in their score. The scoring of a test is mechanically complex, but conceptually simple. Because each examinee receives a tailor made test, the difficulty of the test can vary quite a bit. The Board of Registry transforms the person ability estimates into scaled scores that can range from 100 to 999 with 400 as passing.