IRT stands for Item Response Theory, which is a statistical and psychometric framework used in educational and psychological measurement. It is a theoretical approach to modeling and analyzing responses to items or questions in tests, assessments, or surveys.
In IRT, the focus is on understanding the relationship between a person's ability or trait and their responses to a set of test items. It is based on the assumption that the probability of a particular response to an item depends not only on the difficulty of the item but also on the ability or trait being measured.
IRT models help in estimating a person's ability or trait level by analyzing their responses to a series of test items with known properties. These models also provide information about the characteristics of the items, such as their difficulty and discrimination parameters.
One of the key advantages of IRT is its ability to provide more precise and reliable estimates of abilities or traits compared to classical test theory approaches. It allows for the development of item banks from which tailored tests or adaptive tests can be created, ensuring that each examinee receives items that are matched to their ability level.
IRT has applications in various fields, including educational testing, psychology, health sciences, market research, and social sciences, where understanding and measuring latent traits or abilities of individuals is of interest.
