According to the weak local independence approachto defining dimensionality, the fundamental quantitiesfor determining a test’s dimensional structure are the covariancesof item-pair responses conditioned on examineetrait level. This paper describes threedimensionality...

Latent class models for cognitive diagnosis have been developed to classify examinees into one of the 2<Superscript> K </Superscript> attribute profiles arising from a K-dimensional vector of binary skill indicators. These models recognize that response patterns tend to deviate from the ideal responses that would arise if...</superscript>

A trend in educational testing is to go beyond unidimensional scoring and provide a more complete profile of skills that have been mastered and those that have not. To achieve this, cognitive diagnosis models have been developed that can be viewed as restricted latent class models. Diagnosis of...