The Hawthorne effect is the increase in worker productivity created by the psychological stimulus of being singled out and made to feel important. It concludes the abilities of a person are imperfect predictors of job performance.
The inclination of people who are the subjects of an experimental study to change or improve the behavior being evaluated only because it is being studied, and not because of changes in the experiment parameters or stimulus....
The Hawthorne Effect is when subjects, in a study or experiment, improve a certain aspect of their behavior, just because they are being studied or watched. You can find more information here: http://en.wikipedia.org/wiki/Hawthorne_effect
The Hawthorne Effect is the process where the subjects of an experiment change their behavior because they know they are being studied. The subjects increased their output because of their awareness of being observed. It was named after where the experiment took place at the Hawthorne Works.