言語水準と媒介過程

Kendler仮説の検討

抄録

Kendler and D'Amato applied a mediational theory to predict that reversal shift would yield positive transfer for college students, and found, as predicted, that theyd behaved in a manner opposite to the albino-rats on which they had studied before, i. e. reversal shift was faster than nonreversal.
Then, H. H. Kendler and T. S. Kendler used the same technique to study concept learning in lindergarten children. Its purpose was again to see whether the behavior of the children would be consistent with the single-unit or the mediational type of S-R theory.
However, the results were that the group, as a whole, showed neither positive nor negative transfer in the test situation. Slow learners performed according to the single-unit theory: like the albinorats, they showed negative transfer for reversal shift. Only fast learners performed in accordance with the mediational theory; like the college students, they showed positive transfer for reversal shift.
Therefore, Kendler's mediational theory which implies that the mediation is verbal process, was not fully confirmed yet. This was why we planned a series of experiments on kindergarten children and tried to make sure directly how the verbal or symbolic clue mediated between the external stimuus and the overt response.
Method: Subjects-The Ss were kindergarten children (ages 3 to 6yrs. old). They were divided into two groups on the basis of their speech levels. Screening test trials were given to 243 children, and those who were able to express their choice verbally were put in the H-group. Those who were unable were put in the L-group. Then, each group was divided into two again, one for reversal shift (R-group) and another for nonreversal shift (NR-group).
Then, half of each group was instructed to tell E. their choice before they actually pointed it with a finger, i. e. they were expected to use words, e. g.“little,” “big,” or “green.” Those groups were called “overt verbalization groups”(OV-groups). So our experimental groups numbered 8 in all and
8 children in each group.
We predicted the results as follows:
1) When the Ss were not given any instruction to tell E. their choice, R-shift would be faster than NR-shift in the H-group, and NR-shift would be faster than R-shift in the L-group.
2) When the Ss were on a high level in their speech, R-shift would be faster than NR-shift, and OV would have little or no effect on R-shift, but it would interfere with NR-shift.
3) When the Ss were on a low level in their speech, OV would reinforce completing R-shift, but would have little effect on NR-shift, or impair it a bit. When the correct verbal clue was given, R-shift would be faster than NR-shift. When they were not given, NR-shift would be completed more quickly than R-shift.
Differing from our predictions, the results of our experiments showed that R-shift was always faster than NR-shift not only in the H-group but in the L-group. The OV seemed to yield positive transfer for R-shift, but it was not statistically reliable.
Discussion: As all the Ss. we used had already experienced an amount of test trials for screening, we found it possible to think that a. categorization set had been formed by it and it played the role of covert responses that were assumed to mediate between external stimuli and overt responses.