Intended for healthcare professionals

Rapid response to:

Endgames Statistical Question

The Hawthorne effect

BMJ 2012; 344 doi: (Published 04 January 2012) Cite this as: BMJ 2012;344:d8262

Rapid Response:

Author's Reply: The Hawthorne effect

I thank Smith for his (second) rapid response[1] to my endgame on the Hawthorne effect[2], providing me with the opportunity to discuss the Hawthorne effect further. Claims of selective misquoting in my original article are false, and paradoxically it is Smith who would appear to have selectively misquoted the evidence.

Whilst Smith quoted directly from the report of the re-analysis of the data from the original studies, the last and most important sentence of the synopsis was omitted without explanation. To quote directly and in full (

“The “Hawthorne effect,” a concept familiar to all students of social science, has had a profound influence both on the direction and design of research over the past 75 years. The Hawthorne effect is named after a landmark set of studies conducted at the Hawthorne plant in the 1920s. The first and most influential of these studies is known as the “Illumination Experiment.” Both academics and popular writers commonly summarize the results as showing that every change in light, even those that made the room dimmer, had the effect of increasing productivity. The data from the illumination experiments, however, were never formally analyzed and were thought to have been destroyed. Our research has uncovered these data. We find that existing descriptions of supposedly remarkable data patterns prove to be entirely fictional. There are, however, hints of more subtle manifestations of a Hawthorne effect in the original data.”

So therefore the re-analysis of the original data never indicated the Hawthorne effect did not exist, only that it was more subtle than originally suggested. Why Smith selectively misquoted the original article is unclear. However, subsequent claims that the Hawthorne effect is a myth (as it would appear that Smith does) are false. The Hawthorne effect is very much alive and kicking. References to recent research on the Hawthorne effect are provided in my earlier reply[3] to Smiths first rapid response.[4]

1. Smith BJ. Re: The Hawthorne effect. 11 April 2012.
2. Sedgwick P. The Hawthorne effect. BMJ 2012;344:d8262.
3. Sedgwick P. The Hawthorne effect. 24 January 2012.
4. Smith BJ. Re: The Hawthorne effect. 9 January 2012.

Competing interests: No competing interests

24 August 2015
Philip M. Sedgwick
Reader in Medical Statistics and Medical Education
St. George's, University of London
Cranmer Terrace, Tooting, London SW17 0RE