Final answer:
The sight of a nurse's white uniform would be classified as a conditioned response (CR) in Pavlov's terminology because it has become associated with the fear and pain of an injection.
Step-by-step explanation:
In the scenario presented, a young child has learned to associate the sight of a nurse's white uniform with the fear and pain of getting an injection. According to Pavlov's terminology, when the white uniform elicits a fear response, it would be termed a conditioned response (CR). This is because the white uniform, originally a neutral stimulus, has become associated with the unpleasant experience of getting an injection, which is the unconditioned stimulus (UCS). The fear, which is now triggered by the white uniform alone, was not originally associated with it, making it a conditioned response.
For further understanding, in Pavlov's experiments with dogs, the sight or smell of food was the unconditioned stimulus (UCS) and salivation was the unconditioned response (UCR). When a neutral stimulus, like the ringing of a bell, was paired with the food, it eventually triggered salivation without the food present, becoming a conditioned stimulus (CS) and causing a conditioned response (CR).