Hawthorne effect - rubbish or still relevant?
A useful article that covers the mis-interpretations
http://www.overcomingbias.com/2008/02/the-hawthorne-e.html
that links to 2 interesting studies
http://jech.bmj.com/content/42/3/304.abstract
http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&uid=8859912&cmd=showdetailview&indexed=google
