Premack Principle
In Plain Language
A more likely activity can reinforce a less likely activity when access depends on doing the less likely one.
ABA Definition
Contingent access to a higher-probability response can reinforce a lower-probability response under the relevant conditions.
Everyday Example
Access to a favorite hobby after a routine chore may increase doing that chore.
ABA Example
A chosen high-preference activity follows an agreed learning response, and data show that response increases.
How It May Be Used
A first–then statement alone does not establish reinforcement. Essential needs should not be made conditional.