Paul E. Newton provides an insightful and scholarly overview of central issues in validity theory. As he notes, many of the conceptual problems in validity theory derive from the fact that the word "validity" has two meanings. First, it indicates "whether a test measures what it purports to measure." This is a factual claim about the psychometric…

Humphry (this issue) has written a thought-provoking piece on the interpretation of item discrimination parameters as scale units in item response theory. One of the key features of his work is the description of an item response theory (IRT) model that he calls the logistic measurement function that combines aspects of two traditions in IRT that…

In this commentary, the author points out few issues, one being that there are models mislabeled as diagnostic, which deal with linear decompositions of item difficulties rather than estimating multidimensional skill variables. The author discusses the issue that there are many new names for essentially well-known models for multiple simultaneous…

As Rupp and Templin (2008) stated directly, diagnostic classification methods "are confirmatory in nature." Methods, though, are neither inherently confirmatory nor exploratory. Diagnostic classification modeling, with its analytical and computational obstacles eventually yielding as a comprehensive and potent discipline emerges, will…

The paper by Rupp and Templin (2008) is an excellent work on the characteristics and features of cognitive diagnostic models (CDM). In this article, the authors comment on some substantial and methodological aspects of this focus paper. They organize their comments by going through issues associated with the terms "cognitive,"…

Diagnostic assessment is currently an active research area in educational measurement. Literature related to diagnostic modeling has been in existence for several decades, but a great deal of research has been conducted within the last decade or so, especially within the last five years. The author summarizes the key components in the application…

This article represents a first turn of talk in an ongoing dialogue. Our focus here is on the value of sustained dialogue across the boundaries of research discourses. We argue that such dialogue can illuminate the categories of thought and action (Bourdieu & Wacquant, 1992) that "we" in a given discourse take for granted, situate them as choices…

The last century was marked by dazzling changes in many areas, such as technology and communications. Predictions into the second century of testing are seemingly difficult in such a context. Yet, looking back to the turn of the last century, Kirkpatrick (1900), in his American Psychological Association presidential address, presented fundamental…