| Introduction |
| So, at this point, you've demonstrated that
Sniffy will press the lever when doing so produces pellets. As it turns
out, Skinner had a similar preparation until one day he counted his remaining
food pellets and realized that there were not enough to continue that evening.
Hoping to conserve pellets, he rigged the dispenser to only deliver
food after every other response. Skinner discovered that his rats generally
responded at an even higher rate during intermittent reinforcement than during
continuous reinforcement. The purpose of this assignment is to train Sniffy to eventually respond on an FR-50 schedule of reinforcement. Because this is your fourth Sniffy assignment, you should be pretty comfortable with Sniffy and I will only provide a brief set of instructions. However, if you need any help, please feel free to email me or come by my office. |
| Instructions |
| 1. Start Sniffy Lite. 2. Close the "Operant Associations" window. 3. Open the data file you created from assignment two (the one where you've got him responding pretty consistently on an FR-1 schedule). 4. Change the schedule of reinforcement from FR-1 or CRF to FR-50. Sniffy will probably soon stop responding just like it did for Assignment 3. When he stops or when you've demonstrated that he doesn't stop at FR-50 (by running it out for a while, i.e., 4 intervals) go on to the next step. 5. Change the schedule of reinforcement back to FR-1. Stay here until responding stabalizes. 6. Gradually increase the ratio requirement from FR-1 to FR-50. You should use at least 5 steps (e.g., FR-4, FR-10, FR-20, FR-35, FR-50, etc...) and each step should be a fixed-ratio (not variable-ratio or time-based). Remain at each step until responding stabalizes. When you get to FR-50, stay there until the data stabalize. 7. Save your data file!!! Make sure you name it something different (e.g., "assign4"). |
| Assessment |
| Print out your entire cumulative record. You
may have noticed that running Sniffy for a long time takes up several cumulative
record windows. If you click on "Window" at the top of the screen,
you'll see them all listed. You'll have to print them out each individually
by clicking on each one and then clicking on "File" -> "Print Window."
Staple your cumulative records together and write your name on the
top. Your grade will be determined by the degree to which your cumulative record maps on to the instructions above. Specifically, I'll be looking to see if you've met the criteria that were underlined. By stable, you should remain at that point for at least 4 intervals. Also, please write the assignment number by your name. |