There are several techniques that increase the precision of subscores by borrowing information from other parts of the test. These techniques have been criticized on validity grounds in several of the recent publications. In this note, the authors question the argument used in these publications and suggest both inherent limits to the validity…

Diagnostic scores are of increasing interest in educational testing due to their potential remedial and instructional benefit. Naturally, the number of educational tests that report diagnostic scores is on the rise, as are the number of research publications on such scores. This article provides a critical evaluation of diagnostic score reporting…

In this commentary, the authors discuss some of the issues regarding the use of diagnostic classification models that practitioners should keep in mind. In the authors experience, these issues are not as well known as they should be. The authors then provide recommendations on diagnostic scoring.

In educational testing, subscores may be provided based on a portion of the items from a larger test. One consideration in evaluation of such subscores is their ability to predict a criterion score. Two limitations on prediction exist. The first, which is well known, is that the coefficient of determination for linear prediction of the criterion…

In item-response theory, if a latent-structure model has an ability variable, then elementary information theory may be employed to provide a criterion for evaluation of the information the test provides concerning ability. This criterion may be considered even in cases in which the latent-structure model is not valid, although interpretation of…