Item Response Theory Models and Testing Practices: Current International Status and Future Directions ٭ ٭Invited paper presented at the 23rd International Congress of Applied Psychology, Madrid, Spain. ٭Laboratory of Psychometric and Evaluative Research Report No.229. Amherst, MA: University of Massachusetts, School of Education.

Psychological testing has been undergoing major changes. One of the main changes is the transition from the use of classical to modern test models and methods in test development. The purposes of this paper are to describe the shortcomings of classical test models which are overcome with modern test theory, i.e., item response theory, to introduce the basic concepts of item response theory, to describe several important international applications of item response theory models, and finally, to describe some likely IRT directions in the next century.