The purpose of this study is to illustrate the use of functional data analysis (FDA) as a general methodology for analyzing person response functions (PRFs). Applications of FDA to psychometrics have included the estimation of item response functions and latent distributions, as well as differential item functioning. Although FDA has been…

"Game-Based Assessments: A Promising Way to Create Idiographic Perspectives" (Adrienne Walker and George Englehard) comments on: "How Task Features Impact Evidence from Assessments Embedded in Simulations and Games" by Russell G. Almond, Yoon Jeon Kim, Gertrudes Velasquez, and Valerie J. Shute. Here, Walker and Englehard write…

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 journal issue, the authors of the focus articles have provided a suite of very stimulating and thoughtful articles. The overarching purpose of this research is to explore the application of principles derived from the view of validity proposed by Kane (2004) to their research on issues related to the measurement of mathematical knowledge…