The construction of subjective brightness scales from fractionation data: a validation.

Abstract

Advocates of sensory measurement claim that the fractionatioh procedure permits the assignment of conventional numerals to represent the magnitude of sensory experience. Others have disputed this claim, stating that such numerals do not carry conventional meaning until shown to do so. Campbell and Irwin (i), for example, in discussing the sone scale, say that if such a scale, based on guesses of J, represents equally well guesses of | or A, then there would be some justification for the assumption that the 'i' has meaning in the conventional sense. But since this is not true and because other conditions are not fulfilled, ". . . subjective measurements of loudness in numerical terms . , . are mutually inconsistent and cannot be the basis of measurement."This criticism has not been satisfactorily invalidated. As Campbell and Irwin state, there are inconsistencies among the numerical values based on various types of estimates. Nearly all of the fractionation expert* ments calling for estimates other than J have made use of the loudness continuum. These different sets of data have shown varying degrees of agree-

The judgment of distance on a plane surface

“…Experiment 1 tested directly for the possibility of providing a metric representation of distance judgments by comparing a number of median distance scales constructed independently from different subsets of judgments. This strategy has commonly been adopted in testing the validity of scaling procedures (Chatterjea & DasGupta, 1966;Guilford & Dingman, 1954;Hanes, 1949). line fitted to the variable settings by least squares so as to pass through the origin (this time using all available measurements).…”

Measurement of sensory intensity

“…Brightness of luminous fields. The "brill" scale for brightness (Hanes 1949a;1949b) employed conditions designed to approximate radar viewing since ". .…”

“…The experiments on half brightness and twice distance by Warren and Warren (1958) were designed to obtain answers to the following four questions: 1. could the bril scale be replicated in our laboratory using conditions employed by Hanes (1949a;1949b) and by S. S. Stevens (1961); 2. would judgments equivalent to those of the bril scale be obtained by a separate group of subjects instructed to estimate the effect of doubling distance from the source under bril viewing conditions as required by the physical correlate theory; 3. would double distance estimates follow the inverse square law under "ideal" viewing conditions (adaptation to ambient intensity, contiguous visual fields); 4. under the viewing conditions used for (3), would the group instructed to make subjective brightness judgments also make judgments in keeping with the inverse square law, as predicted by the physical correlate theory. Question (1) represented a sort of calibration designed to determine whether the values we obtained would correspond to those reported in conventional scaling experiments.…”

Bloch’s law and a temporal integration model for simple reaction time to light

“…Brightness (S) has been shown in many magnitude estimation experiments, 421 e.g., Hanes (1949), Hopkinson (1956), Onley (1961, Raab (1962), and Stevens and Galanter (1957), to be closely fit by a power function of physical intensity (S = QIl). The exponent ((3) of the power function in the case of a visual stimulus ranges from about .3 to .5, depending on angular size (large to small, respectively) and retinal position (peripheral to foveal, respectively), and has been recognized to be about one-third, as a general rule of thumb, cf.…”