The purpose of this paper is to clarify the seemingly discrepant views of test theorists and test developers about terminology related to the evaluation of test content. The origin and evolution of the concept of content validity are traced, and the concept is reformulated in a way that emphasizes the notion that content domain definition,…

Modified Parallel Analysis (MPA) is a heuristic method for assessing "approximate unidimensionality" of item pools. It compares the second eigenvalue of the observed correlation matrix with the corresponding eigenvalue extracted from a "parallel" matrix generated by a unidimensional and locally independent model. Revised…

A scaling procedure is proposed, based on item response theory (IRT), to fit non-hierarchical test structure as well. The binary scores of a test of English were used for calculating the probabilities of answering each item correctly. The probability matrix was factor analyzed, and the difficulty intervals or estimates corresponding to the factors…