Evaluation Glossary

Hawthorne Effect

When people know that they are being observed and someone is interested in them, their production increases. Researchers must be aware that the mere fact that they are making changes may cause changes in the behaviour of people. It is wise to ensure that your measuring does not affect the process you are trying to measure.


US Environmental Protection Agency. (2007). Program Evaluation Glossary. Office of the Administrator/Office of Policy/Office of Strategic Environmental Management/Evaluation Support Division.

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