Sage-Tips

What did you understand about item response theory elaborate your answer?

The item response theory (IRT), also known as the latent response theory refers to a family of mathematical models that attempt to explain the relationship between latent traits (unobservable characteristic or attribute) and their manifestations (i.e. observed outcomes, responses or performance).

What role does item response theory play in assessment?

In the place of reliability, IRT offers the test information function which shows the degree of precision at different values of theta, θ. These results allow psychometricians to (potentially) carefully shape the level of reliability for different ranges of ability by including carefully chosen items.

What are the assumptions of IRT?

Several key assumptions underlie the IRT framework, including (i) unidimensionality of the measured trait, (ii) local independence, (iii) monotonicity, and (iv) item invariance. Unidimensionality assumes that a set of items on a scale measure just one thing in common.

How do you conduct IRT?

Although not exhaustive, the general steps involved in an IRT analysis include (1) clarifying the purpose of a study, (2) considering relevant models, (3) conducting a preliminary data inspection, (4) evaluating model assumptions and testing competing models, and (5) evaluating and interpreting results.

What is the difference between CTT and IRT in relation to standard error of measurement?

The most important difference between CTT and IRT is that in CTT, one uses a common estimate of the measurement precision that is assumed to be equal for all individuals irrespective of their attribute levels. In IRT, however, the measurement precision depends on the latent-attribute value.

What is Item Response Theory in psychology?

Item response theory (IRT) is concerned with accurate test scoring and development of test items. You design test items to measure various kinds of abilities (such as math ability), traits (such as extroversion), or behavioral characteristics (such as purchasing tendency).

What is Item Response Theory in SAS?

Xinming An and Yiu-Fai Yung, SAS Institute Inc. Item response theory (IRT) is concerned with accurate test scoring and development of test items. You design test items to measure various kinds of abilities (such as math ability), traits (such as extroversion), or behavioral characteristics (such as purchasing tendency).

What is the Rasch model in IRT?

The Rasch model is one of the most widely used IRT models in various IRT applications. Suppose you have Jbinary items,X1; : : : ; XJ, where 1 indicates a correct response and 0 an incorrect response. In the Raschmodel, the probability of a correct response is given by

What is the difference between classical test theory and IRT?

Therefore, its main purpose focuses on establishing the individual’s position on that continuum. Classical Test Theory [Spearman, 1904, Novick, 1966]focuses on the same objective and before the conceptualization of IRT; it was (and still being) used to predict an individual’s latent trait based on an observed total score on an instrument.