Question

why would positive reinforcement not work at times?
the award isnt effective for the individual
its too nice
skinner didnt practice it first

Explanation:

Positive reinforcement relies on rewards that motivate an individual. If the award is not appealing or effective for the person, it won't reinforce the behavior. Being "too nice" is not a valid reason, and Skinner's personal practice is irrelevant to its effectiveness in real - life situations.

Answer:

The award isn't effective for the individual