A Theoretical and Empirical Study of Scale Properties of Magnitude-Estimation and Category-Rating Scales

Even upon the assumption that magnitude estimates are based on ratio judgments, it is thus not possible to determine the scale type of a magnitudeestimation scale. Necessary conditions cannot be tested simply because the available data are magnitude estimates and not ratio judgments. Magnitude estimates themselves are just numbers and thus give us no information at all concerning their uniqueness, i.e., scale type. An analogous argument applies, of course, to the uniqueness of category-rating scales.