Test assembly item response theory pdf

The new psychometrics item response theory classical test theory is concerned with the reliability of a test and assumes that the items within the test are sampled at random from a domain of relevant items. Item response theory irt is concerned with accurate test scoring and development of test items. A primer on classical test theory and item response theory for. To evaluate the vfq25 using an irt model, the item parameters were calibrated and associated statistics and graphics were produced using irtpro version 2. Population dependent statistics ctt versus population independent statistics irt. Item response theory and computerized adaptive testing. South carolina read to succeed act, south carolina general assembly section 59. Item response theory, item response models, testing practices. Item response theory and computerbased testing in r. Using classical test theory, item response theory, and.

Discussion classical test theory and irt are widely used to address. Item response theory irt comprises a set of generalized latent variable models designed specifically for data arising from educational and psychological tests and questionnaires. Information is the analogue of reliability in classical test theory, but it has some important advantages. Another branch of psychometric theory is the item response theory irt. Item response theory irt has grown from its roots in postwar mentaltesting problems, through. It is sometimes referred to as the strong true score theory or modern mental test theory because irt is a more recent body of theory and makes stronger assumptions as compared to classical test theory. Now we turn to general irt modeling for the data matrix x.

Item response theory in automated assembly of parallel test forms. Demonstrating the difference between classical test theory. Classical test theory ctt and itemresponse theory irt classical test theory ctt and itemresponse theory irt are testing item assessment approaches. If it is assumed that the probability density function i. His research interests include test theory, adaptive testing, optimal test assembly, parameter linking, test equating, and responsetime modeling as well as. Comparisons between classical test theory and item. Focus on item performance irt versus total test performance ctt. Pdf test theory, classical test theory researchgate. The most prominent testtheoretical frameworks are classical test theory ctt and item response theory irt including the rasch model. Test theory and the more modern approach of item response theory are discussed in the. Some text that would try to assemble them into a more coherent whole seemed desirable, and it is provided with this pdf document. This is the first in a series of 6 modules that introduces item response theory irt. Comparisons between classical test theory and item response.

A common objective function in irtbased test assembly is based on the test information function. Pdf a primer on classical test theory and item response theory for. In it the differences in irt and classical approaches are introduced, specifically the differences in their. Irt may be regarded as roughly synonymous with latent trait theory. Each individual item can be used for comparison purposes person endorses better rating on hard items the person is higher on the trait person endorses worse rating on easy items the person is lower on the trait items that measure the same construct can be aggregated into longer assessments. Handbook of item response theory routledge handbooks online. The most prominent testtheoretical frameworks are classical test theory ctt and item response theory irt including the rasch.

Samejimas 39 graded response model was selected, which assumes variable slope parameters across the items on the scale. The impact of the choice of the item response theory model. Item response theory models are used for a host of purposes, including item analysis, test form assembly and equating. 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. Within the ctt framework influential quality criteria like objectivity, reliability, and validity as well as methods for assessing them have been developed. The focus of this session is on item response theory irt and how irt is used at mde.

Item response theory in automated assembly of parallel test forms lin. Although valuable, the use of ctt to assemble examinations and to. Irt derives the probability of each response as a function of the latent trait and some item. Item response theory irt comprises a set of generalized latent variable models designed specifically. Test specific statistics ctt versus test independent statistics irt.