Study objectives: The present study replicated animal research on shaping by variation and selection of behavior using conjoint schedules and extended it to spaced responding by humans. Experiment 1: Experimental design: Between-participants design. Setting: Participants pressed a computer mouse button as a response in a small experimental cubicle. Participants: 13 undergraduate students. Independent variables: 2 conjoint schedules that contained a differential-reinforcement-of-low-rate-response (DRL) and a differential reinforcement of either variable interresponse-times (IRTs) or repetitive IRTs, and reinforcement rates of the variability schedules. Measures: Number of DRL responses and IRT variability. Results: The DRL responses increased only when the variability schedule increased IRT variability and its reinforcement rate decreased. Experiment 2: Experimental design: Within-participants design. Participants: 11 undergraduate students. Independent variables: VI values of the variability schedule in the conjoint schedule. Measures: Number of DRL responses, number of responses that met the variability schedule, and a generalized matching equation. Results: The VI value systematically influenced the 2 responses that were reinforced under the conjoint schedule, and the relation between relative response rate and the relative reinforcement rate of these responses. Conclusion: These results suggest that the shaping of spaced responses was enhanced by behavioral variability, based on a function of the relative reinforcement rate of the spaced responses and variable behavior.

Study objective: The present study investigates whether the performance of pigeons can be simultaneously differentiated into absolute and relative discriminative behaviors. Design: After the pigeons learned a conditional discrimination of absolute and relative size using visual shapes as stimuli, tests were conducted to examine whether they could apply the conditional discrimination to novel pairs that differed in size or shape from the training stimuli. Setting: Experimental chamber with a touchscreen monitor. Subjects: Four pigeons. Independent variables: During training, each differential reinforcement of absolute and relative discriminative behaviors was delivered in the presence of a different conditional stimulus. When the conditional stimulus was a green square, the responses to a stimulus of a particular size were reinforced. When it was a red square, the responses to a smaller (or larger) stimulus were reinforced. Results: There was no consistent response tendency under either conditional stimulus. Moreover, the behavior in the presence of one square was partially affected by the pigeon's reinforcement history with the other square. Conclusion: Absolute and relative discriminations were not differentiated with the present procedure, partly because the reinforcement history with one conditional stimulus affected responses in the presence of the other.

Study objective: To investigate effects of using gestures when teaching receptive language to a young child with autism spectrum disorder (ASD). Design: Multiple baseline design across stimuli. Setting: A playroom at a university. Participant: A 6-year-old non-verbal boy with autism spectrum disorder who could imitate simple gestures. Intervention: In Experiment 1, gestures of 3D objects were paired with verbal instructions corresponding to the objects' names. In Experiment 2, 4 interventions were conducted according to the presence of gestures and picture tapping. Measure: Percentage of correct responses in a matching-to-sample task for receptive language of object names. Results: In Experiment 2, the boy acquired receptive language of 3D object names using gestures. The results of Experiment 2 indicated that the most effective procedure was to have him tap the pictures before the gestures were presented. Conclusion: These results suggest that using gestures, even those that are dissimilar to features of an object, paired with verbal instructions may be effective for teaching receptive language of object names to young children with autism spectrum disorder.

Study objectives: To investigate effects of behavioral coaching on place-kicking skills in high school rugby players. Design: Multiple baseline across 3 participants, based on single-case experimental design. Participants: 3 male high school rugby players. Intervention: Correct place-kicking skills were divided into 9 component skills. Behavioral coaching of the 9 skills consisted of instruction, modeling, behavioral rehearsal, and verbal and checklist feedback. Measures: The percentage of correct component skills demonstrated and successful place kicks was calculated for each player in each session. Results: After behavioral coaching, the percentage of correct component skills demonstrated and successful place kicking skills improved in all 3 participants. Conclusion: Behavioral coaching was effective in improving place-kicking skills.

Over 60 years have passed since the first article on the experimental analysis of human behavior (EAHB) was published. The present article describes studies in the experimental analysis of human behavior that I have conducted with my colleagues during the past 25 years on the following topics: schedule performance, history effects, instructional control, private events, and social behavior. Future directions for research on the experimental analysis of human behavior are also discussed.