The June 2008 issue of Computational Statistics and Data Analysis covered an analysis of Excel 2007. These faults and errors are being reviewed for inclusion.

Section 20 has been rewritten with new material based on errors pointed out by Paulo Tanimoto.
The section on RAND is not yet finished. B.D. McCullough has reported some uncertainties about RAND which are to be investigation.

Section 2 was expanded to cover the faults in Excel's "Order of Precedence"

Source: Used to be hosted at http://www.daheiser.info/excel/frontpage.html. Update on 3/16/2013: It moved elsewhere, can someone help us locate the new page where all these errors are documented - I've found some of the stuff, for example here and here, but I'm wondering where this repository has moved. If you have any comments, or have noted some errors or faults with Excel or my findings, please send it by email to "d_heiser@att.net".

List of bugs, inaccuracies and using non-standard formulas:

1. Introduction (update, 12/9/08)
2. General Problems With Excel (update, 9/13/09)
3. Excel Computation and Display Issues (update, 9/30/07)
4. The Testing Program For Accuracy (update, 11/27/07)
5. Univariate Analysis (update, 3/18/08)
6. Analysis of Variance (ANOVA) (update, 8/28/07)
7. Relationships Between X-Y Typs of Data Sets, 12/10/08
8. Covariance and Correlation, 12/10/08
9. Linear Regression, 12/16/08
10. Non-linear Regression, 12/10/08
11. Chart Trendline Regression, 1/2/09
12. Forecast, 12/7/08
13. What-If Solution Tools, 12/7/08
14. Statistical Distributions and Related Functions (update, 8/28/07)
15. Testing for Accuracy and Reliability of Statistical Distributions (update, 8/26/07)
16. Results of New Tests on Statistical Distributions, Discretes (update, 8/28/07)
17. Results of New Tests on Statistical Distributions, Continuous Functions (update, 8/28/07)
18. Results of New Tests on Statistical Distributions, Continuous Cumulative (update, 8/26/07)
19. Results of New Tests on Statistical Distributions, Comtinuous Inverse (update, 8/26/07)
20. Statistical Tests, Tests of Significance and Tests of a Hypothesis (update, 8/28/07)
21. Random Number Generation (update, 12/10/08)
22. The Data Analysis Tool Routines (update, 12/15/08)
23. Graphics, Charts and Visual Displays (update 06/27/09)
24. Add-In Programs, Functions and Routines (unfinished)
25. Bibliography (updated, 9/13/09)
26. Draft Version of Excel 2010 (updated, 12/31/09)

Sample Excel 2003 Files

NOTES (Revised 6/25/08)
Note A: Comments On Teaching/Using Excel
Note B: Excel Versions and Sources
Note C: Microsoft Knowledge Base Articles (KBA's)
Note D: Excel Help From The Internet
Note E: Guide To Excel Statistical Functions, Routines and Tools
Note F: Help Screen Errors
Note G: Data Input Errors
Note H: Some Specific Lists Of Excel Faults
Note I: Improving Documentation
Note J: Ordinal, Nominal and Likert Scale Variables
Note K: New Display Modified Probability Distributions
Note L: Autocorrelation
Note M: An Actual Problem Requiring Unbiased Standard Deviations
Note N: Ranking, Quartiles, Medians and Percentiles
Note O: Averages, Standard Deviations and Pre-centering
Note P: Alternate Algorithms
Note Q: Data Entry For ANOVAs In The Data Analysis Tool Pac
Note R: Linear Regression
Note S: Linear Regression Throught The Origin, Excel 2000
Note T: Singularity, Multi-colinearity, Accuracy And Other Matrix Problems
Note U: Polynomial Regression
Note V: Regression Normal Probability Plot
Note W: Standardized Residuals
Note X: Support In Excel For Tests Of Significance
Note Y: Constructing A Hypothesis
Note Z: Setting Up The Excel Sheet For Calculating P Values
Note AA: Generate Diehard Test Input Files
Note AB: Diehard-II Output For RAND, Excel 2000
Note AC: Marsaglia's MWC256 RNG
Note AD: Diehard-II And -III Output For RAND, Excel 2003
Note AE: Random Number Generator VBA Routines
Note AF: The Wilkinson-Sawitski Series Of Tests On Excel 2007
Note XN: XNUMBERS, A Multi-precision Floating Point Calculus For Excel