Perceived numerosity: A comparison of magnitude production, magnitude estimation, and discrimination judgments Authors
Received: 14 September 1983 Accepted: 02 April 1984 DOI:
Cite this article as: Krueger, L.E. Perception & Psychophysics (1984) 35: 536. doi:10.3758/BF03205949 Abstract
In previous studies, modalities with a higher Weber fraction have tended to have a lower power-function exponent. Within a modality, however, the Weber fraction and power-function exponent for individual subjects were unrelated, and the present study largely confirms this finding for the numerosity dimension. More important than discriminability in the judgment of numerosity were cognitive factors. A single feedback trial considerably reduced intersubject variability on the magnitude-estimation exponent, although it failed to eliminate individual differences completely (precue and postcue exponents correlated signigicantly, r=+.50). Intrasubject variability, by contrast, seemingly did not involve the underlying exponent. As in previous studies, numerosity generally was underestimated and the power-function exponent was 1.08 for magnitude production and .80 for precue magnitude estimation. Contrary to previous results, however, males and females did not differ in exponent, perhaps because the present procedure allowed self-selection of individuals more interested in numerosity tasks.
Download to read the full article text References Auerbach, C.
(1971). Interdependence of Stevens’ exponents and discriminability measures.
CrossRef Baird, J. C.
(1970). A cognitive theory of psychophysics: II. Fechnei’s law and Stevens’ law.
Scandinavian Journal of Psychology
CrossRef PubMed Baird, J. C., Romer, D., & Stein, T. (1970). Test of a cognitive theory of psychophysics: Size discrimination. Perceptual & Motor Skills, 30, 495–501. Burgess, A.
Barlow, H. B.
(1983). The precision of numerosity discrimination in arrays of random dots.
CrossRef PubMed Eisler, H.
(1963). Magnitude scales, category scales, and Fechnerian integration.
CrossRef Graf, V., Baird, J. C.
(1974). An empirical test of two psychophysical models.
CrossRef PubMed Heinemann, E. G. (1978). Discriminability and ratio scaling. In J. C. Armington, J. Krauskopf, & B. R. Wooten (Eds.), Visual psychophysics and physiology: A volume dedicated to Lomn Riggs pp. 157–166). New York: Academic Press. Indow, T.
(1977). Scaling of dot numerosity.
Perception & Psychophysics
CrossRef Kaufman, E. L., Lord, M. W., Reese, T. W.
(1949). The discrimination of visual number.
American Journal of Psychology
CrossRef PubMed Krueger, L. E. (1972). Perceived numerosity. Perception & Psychophysics, 11, 5–9. Krueger, L. E. (1982). Single judgments of numerosity. Perception & Psychophysics, 31, 175–182. Minturn, A. L.
Reese, T. W.
(1951). The effect of differential reinforcement on the discrimination of visual number.
Journal of Psychology
CrossRef Poulton, E. C.
(1979). Models for biases in judging sensory magnitudes.
CrossRef PubMed Siegel, S. (1956). Nonparametric statistics for the behavioral sciences. New York: McGraw-Hill. Stevens, S. S.
(1957). On the psychophysical law.
CrossRef PubMed Stevens, S. S. (1966). Regression effect in psychophysical judgment. Perception & Psychophysics, 1, 439–446. Stevens, S. S.
(1971). Issues in psychophysical measurement.
CrossRef Teghtsoonian, M.
(1965). The judgment of size.
American Journal of Psychology
CrossRef PubMed Teghtsoonian, M., & Teghtsoonian, R. (1983). Consistency of individual exponents in cross-modal matching. Perception & Psychophysics, 33, 203–214. Teghtsoonian, R.
(1971). On the exponents in Stevens’ law and the constant in Ekman’s law.
CrossRef PubMed Teghtsoonian, R., & Teghtsoonian, M. (1978). Range and regression effects in magnitude scaling. Perception & Psychophysics, 24, 305–314. van Oeffelen, M. P., & Vos, P. G. (1982). A probabilistic model for the discrimination of visual number. Perception & Psychophysics, 32, 163–170. Wanschura, R. G.
Dawson, W. E.
(1974). Regression effect and individual power functions over sessions.
Journal of Experimental Psychology
CrossRef Copyright information
© Psychonomic Society, Inc. 1984