All of the following are types of positive reinforcement EXCEPT:

Positive reinforcement involves the addition of a stimulus following a behavior that makes it more likely that the behavior will occur again in the future. This can include various forms of acknowledgment and encouragement that enhance motivation.

In this context, smiles, verbal praise, and applause are all direct and immediate responses that encourage desired behavior. They provide clear acknowledgment of effort or achievement and are intended to reinforce positive behavior effectively.

On the other hand, random feedback may not consistently provide the encouragement or reinforcement needed. While it can be supportive, the sporadic nature of this type of feedback might cause uncertainty and could lack the immediate positive reinforcement that constructs a strong connection between the behavior and the desired outcome. Therefore, it may not effectively reinforce behavior as the other options do.