Smeets, P. M., Schenk, J. J., & Barnes, D. (1995). Establishing arbitrary stimulus classes via identity matching training and non-reinforced matching with complex stimuli. Quarterly Journal of Experimental Psychology, 48B(4), 311-328.
The authors ( researchers at Leiden U, Dept of Psychology, Behavior Analysis Unit, Netherlands) investigated whether training on an identity task followed by non-reinforced matching probes with complex stimuli led to multiple arbitrary matching performances and stimulus classes, in 2 experiments on 16 preschool children (aged 5-5.4 yrs). Ss were exposed to 2-choice match-to-sample tasks, in which the stimuli consisted of colors and geometric forms with the same or different colors. The difference between the programs of Exp 1 and 2 was the change in the sequence of trials. Results show that the tasks produced 3-term arbitrary stimulus classes in all Ss and that the initial conditional discrimination tasks were learnt with great ease. Ss had acquired class-consistent color-form and form-form relations. The results were replicated in Exp 2, where 6 of the 8 Ss demonstrated all tested relations.