A Computer Adaptive Test (CAT) estimates the ability level of the test taker while the test is in progress. This item-by-item estimation allows the test to adapt to the ability level of the test taker dynamically. One of the primary advantages of a CAT is that it yields a shorter and more accurate test than a traditional fixed form, because a traditional test must waste items that are both too easy and too difficult.
Moreover, when an examinee is administered a test via the computer, the computer can update the estimate of the examinee's ability after each item and then that ability estimate can be used in the selection of subsequent items. With the right item bank and a high examinee ability variance, CAT can be much more efficient than a traditional paper-and-pencil test.
Paper-and-pencil tests are typically "fixed-item" tests in which the examinees answer the same questions within a given test booklet. Since everyone takes every item, all examinees are administered some items that are either very easy or very difficult. These easy and hard items are generally wasted effort on the part of the examinee. They provide relatively little information about the examinee's ability level. Consequently, a larger numbers of items are needed to obtain a modest degree of precision.
With computer adaptive tests, the examinee's ability level relative to a norm group can be iteratively estimated during the testing process and items can be selected based on the current ability estimate. Examinees can be given the items that maximize the information (within constraints) about their ability levels from the item responses. Thus, examinees will receive few items that are very easy or very hard for them. This tailored item selection can result in reduced standard errors and greater precision with only a handful of properly selected items.
Team Code’s Computer Adaptive Test system is a method for administering tests that merges existing computer technology with modern measurement theory to increase the efficiency of the testing process.
The advantages of Team Code’s Computer Adaptive Test system include:
- Requires fewer test items to arrive at a more accurate estimate of test-takers' proficiency than pencil-and-paper tests.
- Allows test-takers to receive immediate feedback on their performance. Each test-taker is administered a different set of test questions, enhancing the test's security.
- Scoring takes into account not just the number of questions answered correctly, but which items were answered correctly. A test-taker who correctly answers a more difficult set of questions will score higher than a test-taker who correctly answers an easier set of questions.
- Controls for item exposure both within and across tests.