Item Response Theory (IRT) is a psychometric testing approach used to measure an individual’s psychological characteristics and abilities. It was first developed by psychometrician Frederic M. Lord and statistician Robert C. Novick in the late 1970s (Kolen & Brennan, 2014). IRT has been used in a variety of educational and psychological assessment contexts, such as the measurement of cognitive abilities, personality traits, and academic achievement (Kolen & Brennan, 2014).
IRT is based on a mathematical model that is used to estimate the probability of an individual’s response to a given item on a test or assessment. This model assumes that the item responses are related to the underlying construct of interest (e.g., cognitive ability, personality traits, etc.) and uses item parameters to describe the relationship between the item responses and the construct (Kolen & Brennan, 2014). IRT also accounts for the differences in an individual’s ability to respond to items and provides a way to measure the difficulty of items and the ability of test-takers (Kolen & Brennan, 2014).
IRT has several advantages over other psychometric testing approaches. First, IRT has a higher degree of accuracy due to its ability to measure an individual’s latent trait and provide a more precise estimate of an individual’s ability and performance. Second, IRT can be used to compare the relative difficulty of different items, which can be used to improve the reliability and validity of a test (Kolen & Brennan, 2014). Finally, IRT can be used to compare the performance of different individuals, which can be helpful in assessing differences in aptitude, ability, and achievement (Kolen & Brennan, 2014).
In conclusion, IRT is an effective and accurate psychometric testing approach that can be used to measure an individual’s psychological characteristics and abilities. It has several advantages over other psychometric testing approaches, such as its ability to measure an individual’s latent trait and provide a more precise estimate of an individual’s ability and performance. IRT can also be used to compare the difficulty of different items and the performance of different individuals, which can be helpful in assessing differences in aptitude, ability, and achievement.
References
Kolen, M. J., & Brennan, R. L. (2014). Test measurement: Theory and applications. New York, NY: Routledge.