Compared to traditional test theory, where person measures are typically referenced to the distribution of a population, item response theory allows for a much more meaningful interpretation of measures as they can be directly compared to item locations. However, Stephen Humphry shows that the crucial role of the unit of measurement has been carelessly handled in the social sciences. While, today, in the natural sciences, proper, and meaningful, measurement is inconceivable without establishing a universal unit first, measurement in the social sciences has curiously done without a standard magnitude of whatever has allegedly been quantified. Stephen Humphry shows that the obstacles to measurement in the social sciences, if they are different from those in the natural sciences, are not insurmountable. They are surely no excuse for dubious attempts at "pseudo-quantification." Despite the need for further research concerning, for example, the polytomous Rasch model or the relationship between the unit and precision, Humphry's work represents certainly more than incremental progress.