Answer:
Hawthorne effect
Step-by-step explanation:
The Hawthorne effect refers to a reaction of the workers included in this experiment where their behavior will be modified (their productivity increased) simply because they know they are being observed. The study should be about how changes in the environment affect productivity, but what really affects productivity is the fact that the workers know they are being part of the study.
In the original Hawthorne experiments, if lighting was increased, productivity increased, but if lighting decreased, productivity also increased. So the changes in productivity had nothing to due with lightning conditions, but rather the fact that the workers were being part of an experiment.