Final answer:
The M&M's given to Nadia by her art teacher after spilling water functioned as positive reinforcement, increasing the probability that she would spill water again in order to receive more candy.
Step-by-step explanation:
The M&M's given to Nadia after she accidently spilled water on her painting acted as positive reinforcement.
In operant conditioning terms, positive reinforcement occurs when a behavior is followed by a reward or a positive outcome, which makes the behavior more likely to happen again in the future. In Nadia's case, the act of spilling water (behavior) is followed by receiving M&M's (positive outcome). As a result, Nadia spills water again in the next art class, showing that the behavior of spilling water was increased due to the positive outcome of receiving M&M's previously.
To clarify, the four main concepts in operant conditioning are positive reinforcement, negative reinforcement, positive punishment, and negative punishment. Positive reinforcement involves adding a desirable stimulus after a behavior, like the M&M's, to increase the likelihood of that behavior occurring again. Negative reinforcement involves removing an undesirable stimulus to increase a behavior. Punishment, whether positive or negative, aims to decrease a behavior. Positive punishment adds an unpleasant stimulus, and negative punishment removes a pleasant one in response to undesired behavior.