Computerized adaptive testing

Computerized Adaptive Testing (CAT) is a form of psychological testing and educational assessment where the tests are administered using a computer. This method tailors the test to the examinee's ability level, providing a more accurate measure of an individual's knowledge, skills, or abilities in a specific domain. CAT utilizes an algorithm to select questions based on the test taker's responses to previous questions, thus adapting the difficulty level of the test to the individual's performance in real-time.

Overview

Computerized Adaptive Testing significantly differs from traditional, fixed-form testing. In a fixed-form test, all examinees answer the same set of questions, leading to potential issues with test sensitivity and accuracy, especially for those whose abilities lie at the extreme ends of the ability spectrum. CAT overcomes these limitations by adjusting the difficulty of questions based on the examinee's responses, thereby maintaining an appropriate level of challenge and reducing the number of items needed to accurately assess the examinee's ability.

Methodology

The process of CAT begins with an initial question of medium difficulty. Based on the examinee's response, the computer selects the next question to be easier or harder, aiming to quickly zero in on the examinee's level of ability. This adaptive process continues until the test meets a predetermined stopping criterion, which could be a specific number of questions, a maximum testing time, or a desired level of confidence in the accuracy of the score estimate.

Advantages

• Efficiency: CAT can significantly reduce the number of questions required to accurately assess an individual's ability, leading to shorter test times.
• Accuracy: By tailoring the difficulty of questions to the examinee's ability, CAT provides more precise measurements, especially for those at the extremes of the ability spectrum.
• Security: With a large pool of questions and each test being unique to the examinee, CAT reduces the risk of test content theft and cheating.

Challenges

• Item Pool Development: Creating a comprehensive item pool that accurately covers the domain of interest is resource-intensive.
• Technical Issues: CAT requires reliable computer and network systems to administer tests without interruption.
• Equity Concerns: There are concerns about access to and familiarity with computer-based testing environments across different demographic groups.

Applications

Computerized Adaptive Testing has applications in various fields, including educational assessment, certification and licensure examinations, and psychological testing. It is used by organizations such as the Educational Testing Service (ETS) for tests like the GRE and TOEFL, and by certification bodies in healthcare, IT, and other professional fields.

Future Directions

The future of CAT includes exploring new adaptive algorithms, enhancing the security of test content, and addressing equity concerns related to access and familiarity with technology. Additionally, integrating artificial intelligence and machine learning techniques may further improve the adaptiveness and efficiency of these tests.