Chapter 9

Question 1

Shaping

Answer 1

generating the target behaviour by differentially reinforcing successive approximations to it

Differential reinforcement: at each stage, if a response meets or exceeds a given criterion, it is not reinforced; if not, it is not reinforced

Successive approximation: the criterion for reinforcement at the current stage, is a response that more closely resembles the target behaviour than the preceding stage

Variability: responding must vary so that closer approximations occur and can be reinforced

Question 2

Dimensions of Behaviour that can be shaped

Answer 2

Topography (form)

• Physical movements involved in the behavior
• Extent of follow through on a tennis serve

Frequency

• Number of instances of the behavior in a given time
• Number of dishes washed in 5 minutes

Duration

• Continuous amount of time that the behavior lasts
• Length of time treading water

Latency

• Time between the controlling stimulus and the behavior
• Time between the question “What time is it?” and the response of looking at your watch

Intensity (force)

• Amount of energy expended on the behaviour
• Force of a punch in boxing

Question 3

Factors influencing the effectiveness of shaping

Answer 3

1. Specify final desired behaviour
   • Greater than zero frequency
   Final target behaviour needs good operational definition:
   • precise statement of the final target behaviour increases the changes for consistent reinforcement of successive approximation of that behaviour
   • Final target behaviour should stated in such a way that all of the relevant characteristics of behaviour - its topography, duration, frequency, latency and intensity - are identified
   • The conditions in which the behaviour is or is not to occur should be stated
   2. Choosing the Starting Behaviour
      • Good operational definition
      • Approximation: Should be a behaviour that occurs enough to be reinforced within the session time, and it should approximate the final target behaviour
      • For example, Franks behaviour of walking around the house once is something that he did periodically. This was the closest approximation that he regularly made with respect to the goal of jogging a quarter of a mile
      • Greater then zero frequency
   3. Choosing the shaping
      • Before initiating the shaping program, it is helpful to outline the successive approximations through which the person will be moved in the attempt to approximate the final target behaviour
      • Step size
      • Flexibility
   4. Move along at correct pace?
      • Too fast? - next behaviour has greater than zero frequency
      • Too slow
      • Several rules of thumb to follow in reinforcing successive approximations of a final target response:
      a. Reinforce an approximation at least several times before proceeding to the next step. In other words, avoid
      under-reinforcement of a shaping step. Trying to go to a new step before the previous approximation has been
      well established can result in losing the previous approximation through extinction without achieving the new
      approximation.
      b. Avoid reinforcing too many times at any shaping step. Point a cautions against going too fast. It is also important
      not to progress too slowly. If one approximation is reinforced for so long that it becomes extremely strong, new
      approximations are less likely to appear.
      c. If you lose a behaviour because you are moving too fast or taking too large a step, return to an earlier approximation
      where you can pick up the behaviour again. You also may need to insert an extra step or two.