There is data, with references, here: http://lostgarden.com/2008/09/rules-of-productivity-presentation.html http://lostgarden.com/2008/09/rules-of-productivity-

There is data, with references, here: http://lostgarden.com/2008/09/rules-of-productivity-presentation.html http://lostgarden.com/2008/09/rules-of-productivity-presenta... It was (very lightly) discussed on HN six days ago http://news.ycombinator.com/item?id=971708 http://news.ycombinator.com/item?id=971708 (I posted clickable links to the references, so you don't have to retype them).