“…For a variety of continua, judgments of “ratios” and “differences” of subjective magnitudes appear to be monotonically related (Birnbaum, 1978, 1980, 1982; Birnbaum & Elmasian, 1977; Birnbaum & Veit, 1974; De Graaf & Frijters, 1988; Elmasian & Birnbaum, 1984; Hardin & Birnbaum, in press; Schneider, 1982; Schneider, Parker, & Upenieks, 1982; Veit, 1978, 1980). Because actual ratios and differences would not be expected to be monotonically related in the factorial designs used in this research (Krantz, Luce, Suppes, & Tversky, 1971; Miyamoto, 1983), such experiments provide nontrivial tests of Torgerson's (1961) hypothesis that subjects perceive or appreciate but a single relation between a pair of stimuli, despite instructions to judge “ratios” or “differences.” 1…”