1. Copyright © 2011 Pearson Education, Inc. All rights reserved. Changing the Control of a Behavior with Fading Chapter 9

2. Copyright © 2011 Pearson Education, Inc. All rights reserved. Fading –Gradual change over successive trials of a stimulus that controls a response so that the response eventually occurs to a partially changed or completely new stimulus –Process of slowly removing prompts after behavior is established

3. Copyright © 2011 Pearson Education, Inc. All rights reserved. Fading Useful in a situation in which a stimulus exerts strong control of a response to be taught to occur to some other stimulus Advantages over trial and error procedures: 1.Errors consume time 2.If an error occurs, it tends to occur many times, even though it is being extinguished 3.Nonreinforcement of errors (extinguishing of errors) produces emotional side effects

4. Copyright © 2011 Pearson Education, Inc. All rights reserved. Dimensions of Stimuli for Fading Fading occurs along dimensions of stimuli Dimension – any characteristic that can be measured on some continuum Fading can occur across specific stimulus dimensions and across changes in general situation or setting –Ex: physical structure of room; number of other people present

5. Copyright © 2011 Pearson Education, Inc. All rights reserved. Factors Influencing the Effectiveness of Fading 1.Choosing the final desired stimulus (FDS) –Stimulus that we want to evoke or produce the behavior at the end of the fading procedure –Important to select FDS in whose presence responding will be maintained in natural environment

6. Copyright © 2011 Pearson Education, Inc. All rights reserved. Factors Influencing the Effectiveness of Fading 2.Choosing the starting stimulus – prompt –Stimulus that reliably evokes the desired behavior –Teacher behavior as prompts Physical prompts/physical guidance – touching the learner to guide him appropriately Gestural prompts – pointing, making motions without touching, etc. Modeling prompts – demonstrating correct behavior Verbal prompts – verbal hints or cues –Environmental alterations as prompts Altering the physical environment to evoke desired response –Extra-stimulus vs. within-stimulus prompts Extra-stimulus – something that is added Within-stimulus – alterations to discriminate

7. Copyright © 2011 Pearson Education, Inc. All rights reserved. Factors Influencing the Effectiveness of Fading 3.Choosing the fading steps: –Should be chosen carefully –Need to monitor performance to determine the speed of fading –If student begins making errors, prompts may have been faded too quickly or with too few steps May need to backtrack

8. Copyright © 2011 Pearson Education, Inc. All rights reserved. Guidelines for Effective Application of Fading 1.Choose final desired stimulus 2.Set an appropriate reinforcer 3.Choose the starting stimulus and fading steps 4.Put plan into effect

9. Copyright © 2011 Pearson Education, Inc. All rights reserved. Getting a New Behavior to Occur with Shaping Chapter 10

10. Copyright © 2011 Pearson Education, Inc. All rights reserved. Definition Shaping –Development of a new behavior by successive reinforcement of closer approximations and extinguishing preceding approximations of behavior Five aspects of behavior that can be shaped –Topography – specific movements involved –Frequency – number of instances that occur in a given period of time –Duration – length of time a response lasts –Latency – time between occurrence of a stimulus and the response evoked by that stimulus –Intensity – force of a response; physical effect the response has on the environment

11. Copyright © 2011 Pearson Education, Inc. All rights reserved. Factors Influencing the Effectiveness of Shaping Specifying the final desired behavior –Terminal behavior – final desired behavior –Specify precise behavior and conditions under which it is to occur Choosing a starting behavior –Should be a behavior that occurs often enough to reinforce within session time –Should be a behavior that approximates the final desired behavior

12. Copyright © 2011 Pearson Education, Inc. All rights reserved. Factors Influencing the Effectiveness of Shaping Choosing the shaping steps –Helpful to outline the approximations that will be reinforced Moving along at the correct pace –Reinforce an approximation at least several times before proceeding to the next step –Avoid reinforcing too many times at any shaping step –If behavior is lost because the program was moving too fast, or the steps were too big, return to an earlier approximation

13. Copyright © 2011 Pearson Education, Inc. All rights reserved. Pitfalls of Shaping Shaping can be accidentally applied with unfortunate results –Harmful behaviors may be accidentally shaped Children may not get the necessary shaping to develop basic behaviors –E.g., developing speech

14. Copyright © 2011 Pearson Education, Inc. All rights reserved. Guidelines for the Effective Application of Shaping Select the terminal or final desired behavior Select the starting behavior Select an appropriate reinforcer Develop the initial plan Implement the plan –Tell the learner about the plan before starting –Begin reinforcing immediately following each occurrence of the starting behavior –Never move to a new approximation until the previous one is mastered –If learner stops working, they may have moved up the steps too quickly, steps may not be the right size, or the reinforcer may be ineffective