Definition of Computer Adaptive Assessment
Computer Adaptive Assessment (CAA) is an innovative, online form of assessment in which items are presented in a sequence that is dependent on the correctness of the examinee’s response to the preceding item. Through this process, each examinee is administered a unique set of items that provides an accurate measure of his or her achievement level.

The Process of Computer Adaptive Assessment
In general terms, a computer adaptive assessment presents an examinee with an assessment item of average difficulty. An examinee who answers the initial question correctly receives a more difficult item; an examinee who answers the initial question incorrectly receives a less difficult item. This method of presenting items of varying difficulty continues until the assessment program indicates that the predetermined test termination criteria have been met. A score can then be produced immediately for the examinee, and reports can be generated for the teacher, school administrator, and school authority.

Comparison with Traditional Assessment Methods
CAA assessments differ from paper-and-pencil tests in a number of important ways. For example, rather than having all examinees writing the same test with the same number of items, CAA examinees receive items that are tailored to achievement ability range. Examinees at a low achievement level are not required to respond to items that are very difficult and far beyond their achievement level, thus reducing potential negative psychological effects (e.g., examinees becoming despondent or more test anxious). Similarly, examinees at a high achievement level are not required to answer a number of items that are much too simple for them, thus reducing the potential for boredom in that group of examinees.

Testing on Demand
The potential for testing on demand is another important difference between computer adaptive assessments and paper-and-pencil assessments. Paper-and-pencil tests are composed of the same set of test items. If students were assessed at multiple times during a school year using the same assessment, then some students may remember items encountered during previous test administrations, which could spuriously inflate their scores. Because computer adaptive assessments draw items from a large pool or bank of items, students are less likely to receive the same set of items if they take an assessment multiple times in a year. In addition, students are assigned scores that are on the same score scale. As a result, using CAA, student performance can be measured over time in a more meaningful manner.

Validity and Reliability
This approach to test administration offers a challenging yet fair assessment experience. Typically, examinees who take a computer adaptive assessment require comparatively fewer items to obtain a more reliable measure of their achievement level than if they had taken a paper-and-pencil test. Therefore, for most examinees, the test becomes shorter, which reduces the potential negative effects of test fatigue in the assessment environment. In adaptive testing, the sequence of items administered is based on the examinee’s performance and are maximally informative about the examinee’s achievement level. With this sequence of item selection, tests are shortened without loss of measurement precision because examinees are not required to answer items that provide little or no information about their achievement level.