Ronald Fisher and Some Thoughts on the p-Value
One of the most discussed, debated and controversial issues in medical research is the p-value. I came across Ronald Fisher’s take on this matter in his work, Statistical Methods for the Research Worker, 1925 (the text of this work has been made available online by Christopher D. Green of the York University):
“The value for which P=0.05, or 1 in 20, is 1.96 or nearly 2; it is convenient to take this point as a limit in judging whether a deviation ought to be considered significant or not. Deviations exceeding twice the standard deviation are thus formally regarded ...