The present study was designed to investigate the process of observational learning. Speed of movement of a lever by children was evaluated. During the acquisition period, Ss received either 50 per cent or 100 per cent reinforcement. Half of the Ss who performed during this phase were observed by a peer. During a subsequent nonreward period, children who had been observers now manipulated the lever, while nonobserved Ss continued to perform. During acquisition, movement speeds associated with 50 per cent reinforcement increased over trials while 100 per cent reinforcement produced no speed change. In the subsequent nonreward period, Ss who had experienced 100 per cent reinforcement, either directly or vicariously, increased movement speed, while the 50 per cent conditions tended to slow down.