This article applies to:
Experiment Author: Adapted from STEP and used with permission of Brian MacWhinney
This experiment is concerned with finding out how good participants are at estimating, for instance, the area taken up by type on a printed page. The experiment uses black rectangles that are a particular percentage of a white rectangle and asks participants to say what percentage they think the black rectangle occupies.
In this experiment participants are shown a card with a black square that varies in size for each trial. After the stimuli appears, a response is required estimating the size of the square as a percentage of the total area of the card.
Helson, H., and Bevan, W. (1964). An investigation of variables in judgments of relative area. Journal of Experimental Psychology, 67(4), 335-341.
Cited Experiment Abstract
In 6 different experiments the part-whole proportion illusion reported by Paterson and Tinker was confirmed. The absolute error was most pronounced with proportions of intermediate magnitude but the relative error was greatest with smallest proportions of central area to total area. The error was found to be essentially invariant with changes in the range of relative magnitudes, the orientation of the rectangular stimulus area, and overall field size. However, when a null method of measuring the illusion was employed, the error was severely reduced with an inflection point at a proportion of 70%. The importance of contextual factors in judgements of a relative area is indicated by an inverse relationship between judged size and overall field size of the stimulus series when the comparisons are made within Ss rather than across groups of Ss. This last finding has methodological importance in determining the role of contextual factors in judgement.
Works Cited by the Experiment
Anastasi, A. The estimation of area. J. gen. Psychol., 1936, 14, 201-225.
Bevan, W. & Dukes, W. F. Color as a variable in the judgment of size. Amer. J. Psychol., 1953, 66, 283-288.
Bevan, W., Pritchard, J. F., & Reed, W. G. Single-stimulus judgments of loudness as a function of presentation interval. Amer. J. Psychol., 1962, 75, 612-618.
Helson, H. Adaptation level as frame of reference for prediction of psychophysical data. Amer. J. Psychol., 1947, 60, 1-29.
Hollingworth, H. L. The central tendency of judgment. J. Phil., 1910, 7, 461-469.
Paterson, D. G. & Tinker, M. A. The part-whole proportion illusion in printing. J. appl. Psychol., 1938, 22, 421-425.
Peters, W. Versuch ueber den Einfluss der Form auf die Wahrnehmung der Flaechengroesse. Z. Psychol., 1933, 129, 323-337.
Piaget, J. The psychology of intelligence. London: Routledge & Kegan Paul, 1947.
Trumbo, D. A., Adams, C. A., Milner, M., & Schipper, L., Reliability and accuracy in the inspection of hard red winter wheat. Cereal Sci. Today, 1962, 7, 62-71.
Witkin, H. A., Lewis, H. B., Hertzman, M., Machover, K., Bretnall, P. M., & Wapner, S. Personality through perception. New York: Harper, 1954.