A previous study by Jacobs and Vandeventer had shown that first-graders could learn the skill of double-classification with color and shape relationships in a half hour or less of individualized instruction. When some details of the training task were altered in an intuitively compelling way to tost for transfer, it was found that the trained Ss could also handle double-classification problems with shading and size relations. Since the transfer dimensions had been selected somewhat arbitrarily, subsequent work by Jacobs and Vandeventer mapped out a universe of relations within which transfer could be more meaningfully assessed. The universe consisted of combinations of 12 basic relations. The primary purpose of the present research was to assess transfer from the training procedure of the earlier study within this universe. Subsidiary purposes were to evaluate the effects of more extensive training and to investigate the effectiveness of different trainers.