Fixed-ratio and fixed-interval schedule control of matching-to-sample errors by children.

Nine children, ages 4 through 7 yr, matched-to-sample on fixed-ratio, fixed-interval, variable-ratio, and variable-interval schedules of reinforcement. Simultaneous, zero-delay, and 2-sec delay matching were employed. Distributions of errors, in which the greatest number of errors occurred at the ordinal position immediately after reinforcement with fewer errors occurring at subsequent positions in the ratio, were produced by six of six children on fixed-ratio schedules for zero-delay and both of two children for 2-sec delay matching. Only two children of seven produced similar error distributions on simultaneous matching for fixed-ratio reinforcement. Variable-ratio schedules produced slightly lower accuracy for most subjects and no systematic error patterns for any subject. Error distributions occurred for all of the five children who experienced fixed-interval schedules for zero-delay matching. Peak error production occurred in the second fourth of the interval. Similar patterns were not produced on variable-interval schedules of equal reinforcement density. Schedule control of complex discriminated operants in children resembles control over similar responses of nonhuman animals.