At the end of the test, a proctor logs the student out before the test grade and full results are made available. The laboratory shown in Figure 15.04 is being expanded to include about 60 stations. Items are selected based on the current ability estimate. The procedure is thought to maximize the information about the test-taker's ability level. Test-takers receive few items that seem very easy or very hard.
Testing ceases at a given level that is the test-taker's highest sustainable performance.
IRT looks at items, and expects persons of similar ability to perform similarly on an item. In this terminology, a test is unbiased when all testers having the same skill level have an equal probability of getting the item correct. If persons of similar ability but different gender perform differently on the item, then the item is said to be biased. Implementing Mastery Learning , 2nd edition. Repeatable testing, J. Chem.