Hawthorne effect /hô′thôrn/ , an unintentional, usually beneficial, effect on a person, a group of people, or the function of the system being studied. It is the effect of an encounter, as with an investigator or health care provider, or of a change in a program or facility, as by painting of an office or change in the lighting system. The Hawthorne effect is likely to confound the results of a study or investigation because it is usually present and difficult to identify. It was named for a study in industrial management at the Hawthorne (Illinois) facility of the Western Electric Company.
