Therefore, it is possible to consider the controlling variables for the response “water, please” as involving two factors: a necessary level of deprivation and discriminative stimuli, typically involving a listener who is likely to get you water and a source from which to get the water.
An environmental change or event with the following features:
Precedes the response to which it is functionally related
Increases the effectiveness of a particular stimulus change as reinforcement
The type of environmental event
The cause of the environmental event
The type of stimulus that gains reinforcing effectiveness