Abstract :
McGrath (2005/this issue) has published a very significant article; it is significant because it examines
the substantive issue of construct validity in a simple and informative way, noting the
confusions apparent in how constructs and their variables are defined, used, and interpreted
within the domain of personality and individual differences. This is a careful, thoughtful, article
that quietly proceeds to outline the problems with current thinking and approaches to defining
and using constructs in psychology. McGrath also suggests how some of these problems might
be addressed. I note that McGrath appears to miss what might be considered an obvious rejoinder
to some of his arguments, that is, the use of latent variable and item response theory. Some
consideration is given to these arguments. However, a cursory examination shows that although
these new methodologies offer many opportunities for new stochastic questionnaire data modeling
and the construction of “instant” latent variables, the same problems caused by lack of attention
to measurement and meaning remain. I find I amin agreement with many of the author’s
views and arguments, but I also find myself wondering whether modern psychometrics and individual
differences research methods is now so dominated by psychological statisticians that
any thought of substantive scientific innovation in this area that deals more properly with measurement
and meaning is long gone. I think the answers to the question “What if there was no
psychometrics?” would be most illuminating.
