From: "Niels U. Kristiansen" Subject: stat problem in Excel? Date: Tue, 4 Apr 2000 10:09:25 +0200 Newsgroups: sci.math,microsoft.public.excel.misc Summary: [missing] I found this on the net. Any qualified comment? Regards, Niels Kristiansen, Aarhus University, DK FYI for Excel users Don't rely on the statistics add-in pack supplied for Excel by Microsoft IT GIVES THE WRONG ANSWERS! The following is extracted from an article by Jon Honeyball in PC Pro, Issue 62, December 1999, pp 248-255. "In front of me right now is a paper entitled "On the accuracy of statistical procedures in Microsoft Excel 97", reprinted from the Journal of Computational Statistics and Data Analysis, which is a highly prestigious, refereed academic journal. I might without exaggeration call it 'the bible of computational statistics' and there's arguably no higher reference in the world. The article comes from volume 31, issue 1, 28 July 1999. The abstract for the paper says: 'The reliability of statistical procedures in Excel are assessed in three areas: estimation (both linear and nonlinear), random number generation, and statistical distributions (such as for calculating p-values). Excel's performance in all three areas is found to be inadequate. Persons desiring to conduct statistical analyses of data are advised not to use Excel.' As an opening statement,you must admit that it's a bit of a corker. The paper's authors, BD McCullough and Berry Wilson of the Federal Communications Commission in Washington DC, go on to describe in precise detail how they applied the recently released StRD (Statistical Reference Datasets) from the American National Institute of Standards and Technology to assess the performance of Excel in a wide range of statistical tests. The results are stunningly bad, and, worse still, the paper refers back to work done by Sawitski in 1994 on Excel 4 and the problems reported then are still present in Excel 97. I've run some of the tests myself and they're still there in Excel 2000. The paper, which can't really be argued with, is littered with phrases like 'can be judged inadequate' and 'it can be deduced that Excel uses an unstable algorithm'. The authors find fault with its univariate summary statistics, analysis of variance, linear regression, nonlinear regression, random number generation and so forth. What can I say? If you use the statistics add-on package that ships with Excel, you really better know your stuff because Excel may well come up with wrong numbers. Excel's statistics add-on pack is riddled with potential disaster areas, and since it has been subjected to the best analysis available in the world and found to be wholly lacking, the only applicable words are 'avoid' and 'plague'. Instead, you should buy yourself a decent stats add-on package that has numerical methods that are open to peer review and whose authors know what they're doing (unfortunately, Microsoft's stats-pack team obviously doesn't)."