Equivalence of Pictures and Objects for Very Young Children

24 children at each of 3 age levels (mean ages 24, 29, and 45 months) participated in 2 discrimination transfer tasks. Each subject was trained with objects as training stimuli for 1 problem and with color photographs of objects as the training stimuli for the other. After reaching criterion on the discrimination learning phase of the task, subjects were presented with 12 test trials which included (1) same stimulus set as training (SE-SF), (2) same stimulus set as training, but in a different form (i. e., photographs of objects used during training, or the object rather than their photographs) (SE-DF), (3) different exemplars of the training set stimuli in the same form as the originals (DE-SF), and (4) different exemplars of the training set stimuli in the different form (DE-DF). All children showed above chance level transfer to both the new form and the new exemplars of the original discrimination stimuli. Moreover, the pattern of performance on the 4 types of test trials was very similar for all 3 age groups. Different forms of stimuli (object vs. picture) were almost always responded to equivalently, while significantly less correct responding was found to new exemplars of training items.