Abstract approved: _________________________________________

The spreadsheet has become a common technology tool and is now a predominant form of end-user programming. Some of the same features that make spreadsheets excellent tools for ad-hoc development can introduce errors into the final product. Although a variety of research has been performed investigating methods to detect errors in spreadsheets, little has been done to investigate initial reasoning errors. The spreadsheet error taxonomy developed by Rajalingham, Chadwick, and Knight (2001) includes categories for reasoning errors that have not yet been investigated. Previous studies have categorized errors in existing spreadsheets, but have not analyzed the source of the error. This study investigates the reasoning of college students while developing spreadsheets and examines the reasoning associated with errors generated in spreadsheet development. For this study, a phenomenological qualitative design incorporated a think-aloud protocol, interviews, and recordings of spreadsheet development of three purposefully-selected students. Data sources were analyzed to determine their reasoning, the types of errors produced based on the taxonomy, and associations between reasonin