I got a letter from a reviewer about a recent paper and it seems like
he is asking for something that is... inappropriate. But, I am not
certain that the whole argument would be.
The dv in the study is reaction time. And, one of my hypotheses is
that fast people will tend to show a postitive effect across the
independent variable (A1>A2) while slow people will show a negative
effect (A1<A2). The editor suggested that I perform an analysis that
looked at the interaction between my mean subject RT and my independent
variable A on RT (rt ~ A:subjectrt). But, isn't this wrong given that
one of the independent variables is necessarily related to the
dependent variable? I don't have anything against finding this
interaction in principle. But, it seems to me that performing the
median split I had originally planned and looking at the effect
direction on either side is more appropriate.
Opinions?