Answer:
The Hawthorne effect
Explanation:
The Hawthorne effect is an effect that is related to the participant in an experiment who work harder and perform better in the experiment. In this term, the participants usually change their behavior not because of their self-manipulation but because of the behavior of the researcher.
The haw-throne effect is very important and is used in organizational and industrial psychology. This term is named after the place where it took place. The haw-throne effect is used to describe the relationship between work and the environment in an organization.
Thus when the third class student told that principle is visiting and he will make a report on their bad behavior they start to behave in a good manner.