Dennis: We've found good historical notes a bit hard to come by. Maybe because the pioneers were also protagonists in a battle of words, as champions of the old and the new methods, so had to watch what they said in print!? Anyway, I'll include what references (below) I can lay my hands on, even referring to myself as you suggest! (Some are not quite on the subject....but are in the general area of the geometry of statistics.) Re 6 and 12, you stump me there! Luckily Richard has come to the rescue. My only thought had been that the term N(N+1) is common, with 6=2x3 and 12=3x4. But Richard's ideas are much better and more specific. Kind regards, Dave REF LIST Box, J.F. (1978). "R.A. Fisher, The Life of a Scientist." New York: Wiley. [See pages 122-129. Biographical material (by Fisher's daughter).]<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> Box, G.E.P., Hunter, W.G. and Hunter, J.S. (1978). "Statistics for Experimenters: An Introduction to Design, Data Analysis and Model Building." New York: Wiley. [See pages 197-203.] Bryant, P. (1984). "Geometry, statistics, probability: Variations on a common theme." The American Statistician 38: 38-48. Durbin, J. and Kendall, M.G. (1951). "The geometry of estimation." Biometrika 38: 150-158. Fisher, R.A. (1925). "Applications of ``Student's'' distribution." Metron 5: 90-104. [Foundations of statistics type material.] Heiberger, R.M. (1989). "Computation for the Analysis of Designed Experiments." New York: Wiley. [See geometry sections.] Herr, D.G. (1980). "On the history of the use of geometry in the general linear model." The American Statistician 34: 43-47. Saville, D.J. (2001). "A hands-on, interactive method of teaching statistics to agricultural researchers." In: C. Batanero (Ed.), Training Researchers in the Use of Statistics (pp 197-213). Granada, Spain: International Association for Statistical Education and International Statistical Institute. [Mostly deals with my heuristic-based workshops, but has a small final section on teaching via geometry.] Saville, D. J.; Wood, G. R. (1986). "A method for teaching statistics using n-dimensional geometry." The American Statistician 40: 205-214. [General interest paper.] Saville, D.J. and Wood, G.R. (1991). "Statistical Methods: The Geometric Approach." New York: Springer-Verlag, 560 pp. [Textbook for 2nd year university applied statistics courses.] Saville, D.J. and Wood, G.R. (1996). "Statistical Methods: A Geometric Primer." New York: Springer-Verlag, 268 pp. [Easier reading introduction to the geometric approach.]