The Use of Chaining and Reinforcement in an Obstacle Course Vivian Scott & Elishia Webster Randolph-Macon Woman’s College Lynchburg, VA Introduction Shaping is a training procedure through which the subject is reinforced for every successful approximation of the desired behavior that is produced (Chance, 2006). Every small approximation was immediately reinforced by providing about ¼ of a Froot Loop. Chaining is used to teach the subject to perform each action in a particular sequence (Chance, 2006). The present study used forward chaining. Each link of the chain was reinforced and the last act in the chain (entering the exit box) produced the delivery of a strong reinforcement (pile of Froot Loops). We used continuous reinforcement (CRF) to reinforce the desired behavior each time it occurred. Once the behavior was produced at a steady rate, the ratio of Froot Loops were decreased by stretching the ratio. Today, shaping and chaining is used to train animals and even humans. Carl Cheney (1978) shaped and chained series of behaviors including climbing ladders, walking across a rope, crawling through a tunnel and entering an elevator. We hypothesized that through the use of shaping and chaining the subject will successfully complete the obstacle course without any reinforcements. Our second hypothesis was that the number of reinforcements needed to complete the obstacle course would decrease each day. Method Subject: The subject was a male, Long-Evans rat who was obtained from the Harlan Breeding Company. He was on food deprivation for the duration of the experiment in attempts to keep him at 85% of his normal body weight. Water was provided ad libitum. Apparatus: The obstacle course consisted of a large central box (L:21” x W:17” x H:12”) with two smaller boxes (both measuring L:11” x W:5” x H:4”) at opposite corners as the starting point and ending point for the obstacle course. Inside the large central box there was a small tunnel (3 ½” x 3 ½”), a box (also L:11” x W:5” x H:4”) with a ramp on one end and a tower (11” tall) consisting of five blocks. Procedure: For three days the rat was shaped through the obstacle course through continuous reinforcement by providing a trail of Froot Loops cereal pieces. During Day 1 we ran 5 trials, on Day 2 we ran 7, and on Day 3 we ran 8. A trial consisted of placing the rat in the entry box and dropping Froot Loops along the correct path. A trial was over when the rat correctly finished the obstacle course by entering the ending box or when the rat deviated from the correct path. On Day 3 the rat correctly finished the obstacle course. The baseline number of Froot Loops it took to guide him through the maze was 18. The following 4 days the researchers gradually removed Froot Loops and stretched the ratio of reinforcement, until Day 7, when the rat correctly finished the obstacle course with no reinforcement at all. Discussion -Hypothesis generally supported, as a significant drop in reinforcement needed occurred on two of the three days -Hypothesis supported, as successful completion of the course occurred from Day 4 to Day 7 -Limitations include small number of subjects, environment was distracting with noise -Possible problem may have been the sheer amount of reinforcements needed, as the subject began to show less interest the longer the experimentwent each day -Future research could examine any differences between the use of forward chaining and backwards chaining Results Paired sample t-tests were run in order to examine the difference in the number of Froot Loops needed to complete the obstacle course. The difference from Day 4 (M = 15.50, SD = 1.73) to Day 5 (M = 12.25, SD = 1.50) was statistically significant, with t(3) = 3.15, p.05. The difference between Day 6 (M = 10.00, SD = 4.32) to Day 7 (M = 3.5, SD = 2.52) was statistically significant, with t(3) = 3.43, p <.05. Additionally, a paired sample t-test was conducted to examine the overall difference from Day 4 (M = 15.50, SD = 1.73) to Day 7 (M = 3.5, SD = 2.52), the final day of the experiment. The difference was statistically significant, as t(3) = 8.15, p <.05. References Chance, P. (2006). Learning and behavior: Active learning edition (5th ed.). Belmont, CA: Thomson/Wadsworth Figure 1