Which of the following is not one of the four quadrants of operant conditioning?

The four quadrants of operant conditioning consist of positive reinforcement, negative reinforcement, positive punishment, and negative punishment. Each of these quadrants represents a distinct way in which behavior can be modified based on rewards or consequences.

Positive reinforcement involves adding a desirable stimulus to increase a behavior, while negative reinforcement entails removing an unpleasant stimulus to also increase a behavior. Positive punishment, on the other hand, adds an aversive stimulus to decrease a behavior. Negative punishment involves removing a desirable stimulus to decrease a behavior.

The option indicating "negative reinforcement and positive punishment" combines two valid quadrants but does not capture the complete schema of operant conditioning. This combination therefore cannot stand as a quadrant itself, making it the correct answer to the question regarding which is not one of the four quadrants. It is important to understand the distinct roles each quadrant plays in behavior modification and why they are defined separately.