First presented at CALECO
The revised version of this paper was written during a visit to the Department of Informatics at the University do Minho in Portugal, with the help of a grant from the Fundação para a Ciência e a Tecnologia. Conversations with Peter Broadhurst, Razvan Diaconescu, Paul Emms, Hendrik Hilberdink and Petros Stefaneas played a valuable rôle during MM's inception; and I would like to thank Professor Ray Panko of the University of Hawaii for discussing the subject of spreadsheet errors with me.