David Whittaker

Spreadsheets have errors like dogs have fleas. Nine out of every ten spreadsheets suffer some error, and consequences can be severe.

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

Connexion is a collection of the most useful and interesting spreadsheet-related articles from the web.

Solver Max provides a collection of optimization model examples in Excel (using the Solver and OpenSolver add-ins) and Python.

The twenty principles for good spreadsheet practice aims to reduce the amount of time wasted and the number of errors.

"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.

Once information is loaded into a spreadsheet, it acquires properties that it may not deserve – a process called reification.

See our bibliography of spreadsheet best practice, risk management, errors and testing, and methods for improving spreadsheets.