Andrew Hawker

The cascading structure of typical spreadsheet formulae means that just about every spreadsheet is almost certainly wrong.

We are conscious of very few of our errors. When people are confronted with their actual error rates, they are typically shocked.

Spreadsheets can be considered to be the world's most successful end-user programming language. Spreadsheet formulas are Turing complete.

Errors in the data, formulas, or manipulation of spreadsheets could be costly, even devastating.

Incorrect use of Excel's NPV function is a common source of spreadsheet errors. We show several pitfalls and ways to avoid them.

Our spreadsheet methodology has criteria for designing, building, and validating spreadsheets to ensure that they work correctly.

95% of all spreadsheets contain errors. So, it is almost certain that your spreadsheets are wrong.

"Oh My God" my formulas are not working! This article covers most of the reasons for Excel formulas not working. And how to fix them.