Date of Award:


Document Type:


Degree Name:

Doctor of Education (EdD)




David R. Stone


The purposes of this study were: (1) to compare nine groups of subjects composed of intellectually normal children, mentally retarded adolescents, and mentally retarded adults on a three dimensional concept formation task; (2) to determine the effects of discrimination training on the sortings of the nine groups on the experimental task.

The 207 subjects of this study were divided into nine groups. Seven of t he groups, consisting of high average and low average grade 3, superior high average, and low average grade 6, and high and low adolescent retardates were chosen on the bases of school grade level (3, 6, and adolescent retarded) and IQ level (low average, high average, superior, low and high adolescent, and low and high adult retarded) with each group composed of 21 subjects, except the two adolescent groups which were composed of 30 subjects each. The remaining two groups, high and low adult retardates, were chosen on the bases of chronological age (between 20-35) and IQ level (high and low mildly retarded), with both groups composed of 30 subjects. One-third of the subjects in each group were given special discrimination training with the task objects.

The experimental task required each subject to place 27 objects in three trays which could be moved back and forth. The trays were stacked one on another vertically but separated by one-sixteenth of one inch. Each tray was divided into nine boxes.

The objects were of three kinds: sphere, cube, and tetrahedron; three sizes: 1, 1 1/2, and 1 3/4 inches; and three shades of blue: dark, medium, and light. Each subject was directed to place the objects in the three dimensional matrix as he desired. The discrimination subjects of each group performed the same task, but they received special orientation training with the trays and objects. One task object, a medium sized, medium blue cube was pre-placed in the center box of the middle tray for an anchor point for each subject to use for his sortings. The results of this study indicate the following:

  1. The nine diverse groups included in this study did not show statistically significant differences in their grouping of identical color shades, identical forms and identical sizes in the three dimensional matrix when each element
  2. The nine groups did not significantly (statistically) differ in their use of the left to right direction in their grouping of identical color, identical form, and identical size horizontally as well as vertically. This lack of significance also applied to the use of the front to back direction in sorting color, form and size differences both horizontally and vertically.
  3. Discrimination training did not significantly affect the performance of the nine groups on any of the dimensions measured in this study. Adult and adolescent retarded groups showed noticeable effects from discrimination training by increasing their responses to size likenesses in their horizontal sortings. In general, normal subjects increased their groupings of identical elements more than retarded subjects, hut the findings indicate that IQ and chronological age did not significantly (statistically) affect discrimination training in these nine groups.
  4. Neither chronological age nor IQ significantly (statistically) affected the subjects' concrete tendency to place the largest size objects into the top tray which was most accessible for sorting.