The "Round-to-even" method has served as the ASTM (E-29) standard since 1940. The origin of the terms "unbiased rounding" and "statistician's rounding" are fairly self-explanatory. In the 1906 4th edition of "Probability and Theory of Errors" Robert Simpson Woodward called this "the computer's rule" indicating that it was then in common use by human computers who calculated mathematical tables. Churchill Eisenhart's 1947 paper "Effects of Rounding or Grouping Data" (in "Selected Techniques of Statistical Analysis", McGrawHill, 1947, Eisenhart, Hastay, and Wallis, editors) indicated that the practice was already "well established" in data analysis.