Reviews the use made of computer-assisted stemmatic methods by the Canterbury Tales project from 1990 to 1993. The project uses two methods: phylogenetic analysis (here called "Cladistic analysis"), using Swofford's PAUP program, and database analysis, using an early form of the VBase program, still in use by the Project (as is too PAUP) in 2020. This article gives a fuller account of the work done by the authors on the Old Norse Svipdagsmal tradition, described in their ‘Report on the Textual Criticism Challenge 1991.’ Bryn Mawr Classical Review 3.4 (1992): 331-37. It also introduces and explains the concept of 'Fundamental Witness Groups" which remains central to the Project.