Wiggle Quotes (1 quote)
I asked Fermi whether he was not impressed by the agreement between our calculated numbers and his measured numbers. He replied, “How many arbitrary parameters did you use for your calculations?" I thought for a moment about our cut-off procedures and said, “Four." He said, “I remember my friend Johnny von Neumann used to say, with four parameters I can fit an elephant, and with five I can make him wiggle his trunk.” With that, the conversation was over.
As given in 'A Meeting with Enrico Fermi', Nature (22 Jan 2004), 427, 297. As quoted in Steven A. Frank, Dynamics of Cancer: Incidence, Inheritance, and Evolution (2007), 87. Von Neumann meant nobody need be impressed when a complex model fits a data set well, because if manipulated with enough flexible parameters, any data set can be fitted to an incorrect model, even one that plots a curve on a graph shaped like an elephant!
In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.
(1987) -- 
