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The present study attempted to evaluate experimentally the relationship between two response classes, enuresis and oppositional behavior. One child who had a long history of bed‐wetting was observed in his home setting. Parents' reports and initial observations confirmed that the child was oppositional much of the time. When a timeout operation and differential attention were presented, removed, and presented again, the frequency of oppositional behavior decreased, increased, and decreased accordingly. Fluctuations in enuretic activity also correlated with the presence and absence of the timeout and differential attention operations. The suppression of oppositional behavior and enuretic activity persisted over an 18‐month treatment period. It was suggested that the parental operations performed on oppositional behavior may have led to an increase in the parents' social reward value. Cessation of enuretic activity was explained in terms of a shift in parental reinforcer effectiveness.

Pigeons pecked for food in a two‐key procedure. A concurrent variable‐interval variable‐interval schedule of reinforcement for two classes of interresponse times was arranged on each key. A visual stimulus set the occasion for potential reinforcement of the four operant classes: shorter and longer interresponse times on left and right keys. In Exp. I, the relative frequency of respones on a key equalled the relative frequency of reinforcement on that key. In Exp. II, the relative frequency of an interresponse time equalled the relative reciprocal of its length. In Exp. III, the relative frequency of an interresponse time was a monotonically increasing function of its relative frequency of reinforcement. These functions relating the relative frequency of an interresponse time to its relative length and to its relative frequency of reinforcement were the same as if there had been no second key. Also, the distribution of responses between keys was independent of the relative frequency of an interresponse time on either key. Experiment IV replicated Exp. I except that choices between keys were controlled by a stimulus that signalled the availability of reinforcement on the right key. A comparison of Exp. I and IV suggested that the relative frequency of an interresponse time on one key generally was independent of behavior on the other key, but that the number of responses per minute on a key did depend on behavior on the other key.

Subjects avoided shock by pressing on one lever under an unsignalled condition, but by pressing a separate lever they changed the condition to signalled avoidance for 1‐min periods. Signalled avoidance periods were identified by a correlated stimulus. All eight subjects responded to change the unsignalled schedule to a signalled one. Once contact with signalled avoidance was made, subjects continued responding to remain in that condition. Other tests showed that changeover responding was greater when the correlated stimulus was presented without the signal than when the signal was presented without the correlated stimulus. An analysis based upon shock and shock‐free periods is presented.

When a well‐learned circle versus ellipse discrimination was made impossibly difficult for the subjects (rhesus monkeys), the controlling stimulus‐response topographies were replaced by competing topographies. The identification of two training conditions sufficient to reinstate the original discrimination permitted the following inferences: the original controlling topography had merely decreased in probability of occurrence, whereas the “strength” of the stimulus‐response relation remained unchanged; discriminations along the apparently continuous circle‐ellipse dimension actually involved several distinct stimulus‐control topographies.

Pigeons were trained on a trial procedure in a Skinner box. Each trial began with a fixed‐interval schedule. Responding on this schedule produced a stimulus and a delayed trial outcome. The stimulus signalled whether the forthcoming outcome was reinforcement or nonreinforcement. Thus, the response was an observing response. When reinforcement was the outcome on 20% of the trials, response rates in the fixed interval were higher than when reinforcement was the outcome on 80% of the trials. This result is consistent with the hypothesis that observing responses are reinforced by the information associated with the stimulus signalling reinforcement. The result seems inconsistent with the hypothesis that observing responses are also reinforced by the information associated with the stimulus signalling nonreinforcement.

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Disputing and talking‐out behaviors of individual pupils and entire classroom groups in special education classes and regular classes from white middle‐class areas and from all black poverty areas ranging from the first grade to junior high school were studied. The classroom teacher in each case acted as the experimenter and as an observer. Various means of recording behaviors were used and reliability of observation was checked by an outside observer, another teacher, a teacher‐aide, a student, or by using a tape recorder. Observation sessions varied from 15 min to an entire school day. After baseline rates were obtained, extinction of inappropriate disputing or talking‐out behaviors and reinforcement of appropriate behavior with teacher attention, praise and in some cases a desired classroom activity or a surprise at the end of the week brought a decrease in undesired verbalizations. A reversal of contingencies brought a return to high levels of inappropriate talking with a return to low levels when reinforcement for appropriate talking was reinstated. The experiments demonstrated that teachers in a variety of classroom settings could obtain reliable observational records and carry out experimental manipulations successfully using resources available in most schools.

The acuity of six pigeons was measured in an apparatus that required the birds to make visual discriminations at a distance of 28.75 in. (73 cm) from the stimulus targets. The stimuli were black and white gratings of varying stripe width. A forced choice procedure was used, and both the Method of Constant Stimuli and a descending series technique determined the order of stimulus presentation. Thresholds, obtained by interpolating at the 25% error point on the psychometric functions, ranged from 1.16 to 4.0 min of arc. Thresholds measured in the same apparatus for two human observers were 0.79 and 0.82 min of arc. The descending series design produced lower per cent error rates at the widest stripe value, but otherwise there appeared to be no difference between psychophysical methods. Position preferences occurred in most of the birds; differential per cent error functions and differential latency functions to the two keys illustrate these. Retinal histology revealed shallow, centrally located foveae in the three pigeon breeds used.

Early elements in an operant chain of toilet behaviors were trained in three normal infants and five retarded children. Following that, eliminative behaviors were conditioned by operant procedures. Each child was equipped with an auditory signalling device that gave cues to the learner. Baseline behavior was recorded for a period of five days. The procedure for training consisted of two steps. First, a response was obtained through physical, verbal, and auditory prompts. Second, prompts were faded until the child responded in the presence of the auditory signal. When the device was removed the child performed without the auditory prompt. Parents were instructed in a similar procedure to enhance generalization in the home. Seven of the eight subjects reached a criterion and maintained that behavior during three criterion sessions.

Three severely retarded boys acquired simple form discriminations errorlessly. Each was first taught to press a red key versus a simultaneously present white key. After this discrimination had been established, black figures were superimposed on the red and white keys. Each correct response affected the next trial by delaying the onset of the red stimulus an additional 0.5 sec. Transfer of stimulus control to the figures was indicated when the subjects responded correctly before the onset of the red stimulus. A series of errorless discrimination reversals was accomplished with this technique, during which the number of trials to transfer systematically decreased with successive reversals.