Using Bayesian statistical methods to determine the level of error in large spreadsheets.

Spreadsheets are ubiquitous with evidence that Microsoft Excel, the leading application in the area, has an install base of 90% on end-user desktops. Nowhere is the usage of spreadsheets more extensive or more critical than in the financial sector, where regulations such as the Sarbanes-Oxley Act of 2002 has placed added pressure on organisations to ensure spreadsheets are error-free. This paper outlines the research that has been carried out into the use of Bayesian statistical methods to estimate the level of error in large spreadsheets based on expert knowledge and spreadsheet test data. The estimate can aid in the decision to accept or re-examine a large time consuming spreadsheet.