Two experiments were carried out. The first study was designed to investigate the effects of percentage of reinforcement and the number of correct acquisition trials, when combined, on the number of responses to extinction and rate of lever-pulling of human subjects. The second study was designed to investigate the effects off percentage of reinforcement combined with number of reinforcements on the same dependent variables. Analysis of the data revealed: (1) resistance to extinction in both experiments, was inversely related to the percentage of reinforcement; (2) resistance to extinction was inversely related to the number of reinforcements but was not affected by the number of correct acquisition trials; (3) the mean rate of responding was inversely related to the number of reinforcements but was not affected by either percentage of reinforcement or number of correct acquisition trials; and (4) the number of responses per unit of time increased during acquisition and decreased during extinction in both studies. The results were discussed in relation to theories stemming from previous partial reinforcement studies. / Thesis / Master of Arts (MA)

The purpose of this study was to compare response rates and resistance to extinction in single-task and multiple-task phases. Research was conducted with thirty undergraduate college students in a controlled experimental setting. Each Participant was exposed to 4 treatment phases: single-task, fixed-ratio of one (ST-FR1), multiple-task fixed-ratio of one (MT-FR1), single-task fixed-ratio of 5 (ST-FR5) and multiple-task fixed-ratio of 5 (MT-FR5) all beginning with a baseline phase and reverting back to baseline after the first two conditions were presented. Half of the Participants received the single-task phase first, and the other half received the multiple-task phase first, in order to observe the behavior in transition. A trials-to-criterion measure was used to determine how long it took each Participant’s behavior to adapt to the new contingency in the next phase, which was presented without any signal. The data reveal that regardless of the order of phase presentation it took Participants more than twice as long to reach the criterion in the single-task phases, than in the multiple-task phases.