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)."