SUMMARY
The spreadsheet is one of the most commonly used personal computer applications. Many studies have shown that a very high percentage of spreadsheet models contain serious errors. The use of influence diagrams, which are a visual representation of the relationships among the variables in a problem, to plan the development of a spreadsheet model may reduce the likelihood of the spreadsheet model containing an error. This paper describes an experimental study that tests whether the use of influence diagrams improves spreadsheet modelling practice. The results of the study suggests that influence diagrams do help users to better understand problems, and as a result reduce the likelihood of omitting important variables from spreadsheet models.