Debunking the Hawthorne effect

The Economist reports that two economists at University of Chicago have reanalysed the original data used to establish the Hawthorne effect, namely that any change in work environment, where workers know an intervention is being made, is likely to lead to an increase in productivity (the change used in the studies was increasing or lowering light levels in at the Hawthorne assembly plant). Unfortunately the study set up seems to have yielded an artefact, rather than a result. The lighting levels were changed on a Sunday when the factory was closed. Productivity then rose on the Monday after the change. What the original scientists failed to report was a cycle of productivity levels, high at the the beginning of the week then tailing off by the following Saturday, even when no change was made to lighting levels.

[via John Naughton]