Knowing what was done: uses of a spreadsheet log file

Spreadsheet use in educational environments has become widespread, likely because of the flexibility and ease of use of these tools. However, they have serious shortcomings if the teacher is to understand exactly what students or others have done. It is far too easy for students to replace a formula that gives an apparently unacceptable answer with a number that they believe to be correct. The same concern applies to recorded marks, as well as to business spreadsheets and to other reports that are used for decision-making. While intentionally misleading changes to spreadsheet files receive much attention, simple mistakes are probably more common. Some of these, such as the Trans-Alta Utilities (Globe and Mail, 2003) cut and paste error that cost the firm $24 million (US), have extreme consequences. Few are merely embarrassing. A log file or audit trail, enhanced by suitable filters, can allow both intentional and accidental changes that cause erroneous results to be caught. In order to meet these requirements, we have developed server based software tool (“TellTable”) which allows editing, version control, and auditing of spreadsheet files. Users connect to the server using a standard web browser, and are able to access and edit spreadsheet files in a Java applet in the browser window. TellTable has been used for a pilot study to maintain marks and course information for a multi-section courses with several instructions and teaching assistants. This paper describes the TellTable software and preliminary results of the pilot test. Submitted November 2003; revised January 2004; accepted February 2004.