ABSTRACT
The subnormals are usually drawn from one type of institution, and are then further selected as the result of their performance on a test of 'general intelligence'; their level of ability is sometimes expressed as an IQ but more usually as an MA. In the use of MA controls, the intelligence test is being used as an index of level of cognitive development. Comparison implies that differences may be discovered between the subnormal and normals at the same level of development. The body of research initiated by Gerjuoy and Spitz employed both CA and MA controls. However, the control subjects were only employed in the random-order control condition. Presentation was auditory and sequential for their multi-trial task, with the material consisting of 20 items, 5 each from 4 categories. The major difficulty facing any experimenter employing the above strategy with subnormals is that of the immense inter-subject variability typical of these subjects.
