Abstract :
In this article, I respond to comments provided by Barrett (2005/this issue), Kagan (2005/this
issue), and Maraun and Peters (2005/this issue) in response to my article (McGrath, 2005/this
issue). I agree with many of the points raised in their articles, although I disagree with some of
Maraun and Peters’s conclusions. Topics I address in this response include the meaning of measurement,
the misapprehension that statistics can answer conceptual questions, problems with
the concept of construct validity, and the problem of distinguishing between derived and fundamental
measures.