Editing Operant conditioning (section)

===Stimulus control of operant behavior===
{{main|Stimulus control}}
Though initially operant behavior is emitted without an identified reference to a particular stimulus, during operant conditioning operants come under the control of stimuli that are present when behavior is reinforced. Such stimuli are called "discriminative stimuli." A so-called "[[three-term contingency]]" is the result. That is, discriminative stimuli set the occasion for responses that produce reward or punishment. Example: a rat may be trained to press a lever only when a light comes on; a dog rushes to the kitchen when it hears the rattle of his/her food bag; a child reaches for candy when s/he sees it on a table.

====Discrimination, generalization & context====
Most behavior is under stimulus control. Several aspects of this may be distinguished: 
*'''Discrimination''' typically occurs when a response is reinforced only in the presence of a specific stimulus. For example, a pigeon might be fed for pecking at a red light and not at a green light; in consequence, it pecks at red and stops pecking at green.  Many complex combinations of stimuli and other conditions have been studied; for example an organism might be reinforced on an interval schedule in the presence of one stimulus and on a ratio schedule in the presence of another. 
*'''Generalization''' is the tendency to respond to stimuli that are similar to a previously trained discriminative stimulus. For example, having been trained to peck at "red" a pigeon might also peck at "pink", though usually less strongly.
*'''Context''' refers to stimuli that are continuously present in a situation, like the walls, tables, chairs, etc. in a room, or the interior of an operant conditioning chamber. Context stimuli may come to control behavior as do discriminative stimuli, though usually more weakly.  Behaviors learned in one context may be absent, or altered, in another.  This may cause difficulties for behavioral therapy, because behaviors learned in the therapeutic setting may fail to occur in other situations.