The tendency of humans to temporarily improve their performance when they are aware it is being studied.

During a study on the effect of different lighting levels on productivity, researchers first lowered the lights. Productivity improved. Raised the lights. Productivity was still improved. They returned to the original lighting levels. Productivity was still improved.

	 :	''"Initial improvement in a process of production caused by the obtrusive observation of that process. The effect was first noticed in the Hawthorne plant of Western Electric. Production increased not as a consequence of actual changes in working conditions introduced by the plant's management but because management demonstrated interest in such improvements."'' -- Krippendorff (http://pespmc1.vub.ac.be/:/ASC/HAWTHO_EFFEC.html)

'''But:'''

In recent years, the validity of the Hawthorne experiments have come under fire.  Berkley Rice refers to this famous effect as a myth, calling it the "Hawthorne Defect".  He discusses a recent re-examination of the Hawthorne experiments.  Serious flaws in the experimental environments and procedures cast doubt on the common interpretation of the Hawthorne results.  Defects include replacement of study subjects for failure to show increased productivity, for example.  (http://www.cs.unc.edu/~stotts/204/nohawth.html)

Additionally, subsequent contemporary experiments have found the results difficult to reproduce, when more controls are added.

Note that if those particular experiments are flawed, it does not prove that the conclusions are false, nor that the opposite is true.

''Yeah, just like the inability to replicate particular psychic experiments does not prove that their conclusions are false.''

----
It can be more subtle than the simple fact that people were being "studied." People also like having (non intrusive) attention paid to them. If you're taking an interest in what they're doing, motivation and productivity are likely to rise.

It sounds like the HawthorneEffect is a special case of a placebo effect: the actual level of the light didn't affect anything.  Instead, either the change itself, or else the attention from management itself, caused the effect.

----
PeopleWare's take on the HawthorneEffect is that workers are more productive when they are trying something new.  People are intrigued by novelty.  The recommendation is to do something different with every project--make nonstandard approaches the rule.

The main difficulty in trying to take advance of the phenomenon is that the HawthorneEffect is temporary.  After a short period of time productivity levels return to where they were before.
----
Another take is that the HawthorneEffect has two causes - awareness of a change being made in the environment, and awareness of attention being given. The flaw in the study to me is that the two things were not isolated.
----
CategoryPsychology CategoryWorkEnvironment