According to Freedman et al. (1991, pages 494 and A-27),
R. A. Fisher was one of the rst to publish such tables, and it seems to have been his idea to lay them out that way. There is a limited amount of room on a page. Once the number of levels was limited, .05 and .01 stood out as nice round numbers, and they soon acquired a magical life of their own. With computers everywhere, this kind of table is almost obsolete. So are the .05 and .01 levels.
This history is on the authority of G. A. Barnard, formerly professor of statistics, Imperial College of Science and Technology, London; now retired.
Freedman, D., Pisani, R., Purves, R., and Adhikari, A. (1991), Statistics, New York: Norton,
2nd edition.
R. A. Fisher was one of the rst to publish such tables, and it seems to have been his idea to lay them out that way. There is a limited amount of room on a page. Once the number of levels was limited, .05 and .01 stood out as nice round numbers, and they soon acquired a magical life of their own. With computers everywhere, this kind of table is almost obsolete. So are the .05 and .01 levels.
This history is on the authority of G. A. Barnard, formerly professor of statistics, Imperial College of Science and Technology, London; now retired.
Freedman, D., Pisani, R., Purves, R., and Adhikari, A. (1991), Statistics, New York: Norton,
2nd edition.