International trended assessments have long attempted to provide instructional information to educational researchers and classroom teachers. Studies have shown that traditional methods of item analysis have not provided specific information that can be directly applicable to improve student performance. To this end, cognitive diagnosis models…

Most of the tests and inventories used by counseling psychologists have been developed using CTT; IRT derives from what is called latent trait theory. A number of important differences exist between CTT- versus IRT-based approaches to both test development and evaluation, as well as the process of scoring the response profiles of individual…