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Three experiments were conducted to investigate the theoretical reduction of rate and duration of reinforcement to their product, rate of reinforcement‐time, under concurrent chain schedules. In Exp. I, rate of reinforcement‐time was varied by varying rate of reinforcement delivery, holding duration of reinforcement availability constant; in Exp. II, rate of reinforcement‐time was varied by holding rate of reinforcement delivery constant and varying duration of reinforcement availability; in Exp. III, rate of reinforcement‐time was held constant by varying both rate and duration of reinforcement simultaneously and inversely. For all three experiments, both relative rate of responding and relative time spent in the initial link were found to match approximately the relative rate of reinforcement‐time arranged in the terminal link. These data were interpreted as support for the notion that rate and duration of reinforcement may be functionally equivalent and reducible to a single variable, rate of reinforcement‐time.

The effects of teacher attention on the attending behavior of two boys seated at adjacent desks were investigated. Baseline records were obtained of the appropriate attending behavior of two boys who were described as the most disruptive pupils in a second‐grade classroom of a poverty area school. During the first experimental phase, the teacher systematically increased the amount of attention for appropriate attending in one of the pair, Edwin. This resulted in a dramatic increase in his attending rate and a lesser, though significant, increase in attending behavior of the second boy, Greg. During the second experimental phase, systematic attention for attending was instituted for Greg and was discontinued for Edwin. This resulted in further increases in attending by Greg and a reduction in attending by Edwin. A brief withdrawal of reinforcement for attending in both Greg and Edwin reduced attending levels for both. Following this reversal appropriate attending for both boys was systematically reinforced and attending returned to high levels.

The effects of d‐amphetamine and chlordiazepoxide were studied in pigeons on performance (1) under a schedule that reinforced responses on a key (food key) if they were more than 20 sec apart, (2) under the same schedule when responses also were required on a collateral key during the interresponse time on the food key, and (3) under the same schedule when responses were required on a collateral key during the interresponse time on the food key and collateral‐key responses could produce a stimulus correlated with the availability of food. Under all three spaced‐responding schedules, d‐amphetamine and chlordiazepoxide at low dose levels slightly increased the frequency of short interresponse times on the food key for about half the birds, and either did not affect the interresponse time patterns of the other birds, or lengthened the durations slightly. At higher dose levels, d‐amphetamine and chlordiazepoxide increased the frequency of long interresponse times or abolished responding in all birds. Changes in the pattern of interresponse times on the food key did not seem to depend on changes in the rate or pattern of collateral‐key responses.

Four‐ and five‐yr‐old disadvantaged children were read sentences composed of varying numbers of short phrases. The children were asked to repeat each sentence, but the accuracy of their imitations was not differentially reinforced. The teacher stressed (emphasized) certain words as she read each sentence. The proportion of words that were stressed was systematically varied. In general, the children imitated only parts of most sentences. Stress was effective in influencing which parts of a sentence the children would imitate, but only when relatively few words were stressed. Stressing a word increased the probability of a child's imitating that word (and, to a large extent, the entire phrase containing that word) as an inverse function of the proportion of the words that were stressed.

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