The development of stimulus classes using match-to-sample procedures: Sample classification versus comparison classification

Four experiments were conducted to investigate the development of stimulus classes using matching-to-sample procedures. The first three experiments involved teaching subjects to select four different comparison stimuli in response to a single sample stimulus. In the fourth experiment, the subjects were taught to select a single comparison stimulus in response to four different sample stimuli. Only one of the six subjects who received single-sample, multiple-comparison training demonstrated stimulus class development. All three subjects who were given training in selecting a single comparison stimulus in response to multiple samples demonstrated stimulus class development.