Psychology ETDs

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An analysis of rule learning (RL) data suggests that an important factor in bidimensional concept learning is the degree to which stimuli share common stimulus values. Subjects have the most difficulty with differentially assigned stimuli which have common values and with stimuli which are assigned to the same response category but have no common values. Based on these findings, an experiment was run with four bidimensional stimuli to determine how Ss will respond to non-reinforced test stimuli after the reinforcement of one or two stimuli to the same or different response categories. The data indicated that Ss responded to a single stimulus dimension and that they assigned the test stimuli in opposition to the reinforced stimuli with a high probability if the two stimuli differed on the dimension sampled; the latter tendency is referred to as "negation." A model was proposed in which it is assumed that Ss randomly sample dimensions and compare the "test" stimulus on any trial with a previously reinforced 0comparison ° stimulus. The probability of the assignment of the test stimulus to either of the two possible response categories given a particular comparison stimulus is assumed to be a function of whether or not the two stimuli share a conunon value on the dimension sample. Also, the probability of negation obtained in the experiment is included as a parameter in the model. The model was used to make various predictions for error probabilities on different stimuli and was tested with two types of concepts and two instructional conditions.

In addition, some old RL data were analyzed to determine whether the error probabilities corresponded to the predicted ones. With some exceptions, the predicted error trends were confirmed, and the findings have definite implications for various strategies used in concept learning.

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Level of Degree


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First Committee Member (Chair)

Peter Johnson

Second Committee Member

Richard J. Harris

Third Committee Member

Robert Grice

Fourth Committee Member

Douglas P Ferraro



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Psychology Commons