Abstract
In Experiment 1, subjects were trained on three ill-defined categories represented by 4, 8, and 12 exemplars. Learning was followed by either a classification test on old, new, and random exemplars or a recognition test in which each learning exemplar was presented with two foils, both equidistant to the learning exemplar, but one more similar to the category prototype than the other. In Experiment 2, category size was manipulated between subjects, followed by the recognition test. Recognition data indicated that increasing the number of learning exemplars did not increase the total amount of exemplar information retained for each category. In addition, the more prototypical foil was incorrectly recognized more often than the less prototypical foil. Classification data replicated previous findings that increasing category size in learning enhances classification of new exemplars. The results were interpreted in terms of the relative amounts of categorical and idiosyncratic information that were retained from the original learning stimuli. It was proposed that categorical information can become a more dominant determinant of performance as category size increases.
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Brooks, L. R. Nonanalytic concept formation and memory for instances. In E. Rosch & B. B. Lloyd (Eds.),Cognition and categorization. Hillsdale, N.J: Erlbaum, 1978.
Bruner, J. S., Goodnow, J. J., &Austin, G. A.A study of thinking. New York: Wiley, 1956
Hayes-Roth, B., &Hayes-Roth, F. Concept learning and the recognition and classification of exemplars.Journal of Verbal Learning and Verbal Behavior, 1977,16, 321–338.
Homa, D. Abstraction of ill-defined form.Journal of Experimental Psychology: Human Learning and Memory, 1978,4, 407–416.
Homa, D., &Chambliss, D. The retative contributions of common and distinctive information on the abstraction from ill-defined categories.Journal of Experimental Psychology: Human Learning and Memory, 1975,1, 351–359.
Homa, D., Cross, J., Cornell, D., Goldman, D., &Shwartz, S. Prototype abstraction and classification of new instances as a function of number of instances defining the prototype.Journal of ExperimentalPsychology, 1973,101, 116–122.
Homa, D., &Vosburgh, R. Category breadth and the abstraction of prototypical information.Journal of Experimental Psychology: Human Learning and Memory, 1976,2, 322–330.
Medin, D. L., &Schaffea, M. M. Context theory of classification learning.Psychological Review, 1978,85, 207–238.
Posner, M. I., &Keele, S. W. On the genesis of abstract ideas.Journal of Experimental Psychology, 1968,77, 353–363.
Posner, M. I., &Keele, S. W. Retention of abstract ideas.Journal of Experimental Psychology, 1970,83, 304–308.
Reed, S. K.Psychological processes in pattern recognition. New York: Academic Press, 1972.
Smith, E. E., Shoben, E. J., &Rips, L. J. Comparison processes in semantic memory.Psychological Review, 1974,81, 214–241.
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This research was supported by a grant from the National Institute of Mental Health (5 R01 MH28270).
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Omohundro, J. Recognition vs. classification of ill-defined category exemplars. Memory & Cognition 9, 324–331 (1981). https://doi.org/10.3758/BF03196966
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DOI: https://doi.org/10.3758/BF03196966