What is shaping?
The differential reinforcement of successive approximations of the target behaviour until the target behaviour (“terminal” behaviour) is reached.
What is differential reinforcement?
A schedule of reinforcement where one particular behaviour is reinforced while all other behaviours are not.
What are successive approximations?
Each consecutive behaviour more closely resembles the target behaviour in a series of shaping steps.
What is starting behaviour?
The natural behaviour that is most similar to the target behaviour which we should reinforce.
When should we use shaping?
If the target behaviour is novel.
What are novel behaviours?
Behaviours that often occur during an extinction burst in which many new and radical behaviours are expressed. The next approximation (novel behaviour closest to target behaviour) is reinforced.
What steps should we use when shaping?
- Advance to the next approximation only after the current one has been mastered and can be reliably expressed
- If shaping steps advance too quickly, return to the previous approximation
- Use adequately sized steps, or subject may either become bored (reinforcer will weaken) or learned behaviour will deteriorate
What is quantitative shaping?
Setting criteria to increase or decrease a dimension of an existing behaviour. Dimensions include frequency, duration, latency, and intensity.
What is qualitative (topographic) shaping?
The degree to which successive behaviours resemble the target behaviour.
What has shaping been applied to?
- Physical therapy
- Appropriate classroom behaviours
- Animal training
What are the steps of using shaping?
- Define target/terminal behaviour precisely
- Determine whether shaping is the most appropriate (if someone does not exhibit the target behaviour or if you cannot prompt them to)
- Identify starting behaviour (should be demonstrated by the individual)
- Choose shaping steps/approximations
- Decide what reinforcer to apply
- Apply reinforcement to successive approximations (apply extinction to previous)
- Proceed through shaping steps at appropriate pace
What are the limitations of shaping?
- Can be time-consuming if numerous approximations are necessary
- Progress is not always linear
- Requires behaviour change agent to continuously and closely monitor behaviour to detect the next approximation (time-consuming as well)
- May inadvertently shape problem behaviours (“giving in” reinforces problem behaviours)
