Raju and Oshima (2005) proposed two prophecy formulas based on item response theory in order to predict the reliability of ability estimates for a test after change in its length. The first prophecy formula is equivalent to the classical Spearman-Brown prophecy formula. The second prophecy formula is misleading because of an underlying false…

Psychometric theory focuses primarily on tests that are homogeneous, measuring only one attribute of a psychosocial entity. However, the complexity of psychosocial behavior often requires tests that are heterogeneous, measuring more than one attribute. In this presentation, reliability and internal consistency are extended to heterogeneous tests…

An approach to test modeling is illustrated that encompasses both response consistency and response difficulty. This generative approach makes validation an ongoing process. An analysis of hidden figure items with 60 high school students supports the feasibility of the method. (SLD)