Between numbers and notions - A critique of psychological measurement

When psychologists apply mathematical machinery to psychological ideas, tha t machinery imposes certain requirements in the linkage of numbers and noti ons. These impose choices driven by the mathematics and not the psychology. These decisions, forced by the mathematics, induce theoretical issues in t he psychology. Attempting a theory-neutral approach to research in psycholo gy, where commitments in response to the options are made unknowingly, thus becomes instead a theory-by-default psychology. This paper begins to catal ogue some of these mathematical choices to make them explicit, in order to allow psychologists the opportunity to make explicit theoretical commitment s.