[tips] Re: Question from a student

[Christopher D. Green]

David Howell's large statistics text gives a fairly transparent explanation. Regards, Chris Green ============ Rick Froman wrote: I hope that subject line isn't copyrighted.   After I explained why the formula for the s to predict s uses N-1 in the denominator (to inflate it for a more conservative estimate since it is just an estimate of the population standard deviation), a student asked, why N-1 and not N-2 or N-3? I mentioned statistical studies about how N-1 gives the best estimate of the population standard deviation but I wonder if anyone has a good explanation for why it is N-1. I know if the number got too high, small sample sizes would end up with a negative number (which would make no sense).   Rick     Dr. Rick Froman, Chair Division of Humanities and Social Sciences Professor of Psychology John Brown University 2000 W. University Siloam Springs, AR  72761 [EMAIL PROTECTED] (479) 524-7295 http://www.jbu.edu/academics/hss/psych/faculty.asp "Pete, it's a fool that looks for logic in the chambers of the human heart." - Ulysses Everett McGill --- To make changes to your subscription go to: http://acsun.frostburg.edu/cgi-bin/lyris.pl?enter=tips&text_mode=0&lang=english