For the reduction stage classification, flakes are assigned to four reduction stages based on the presence of certain attributes. Magne (1985; also see Magne and Pokotylo 1981), building on the work of Collins (1975), used discriminant function analyses to determine the best variable for separating flakes produced by experimental reduction into four stages. In Magne’s (1985) scheme, early stage reduction is viewed as all core reduction, middle stage reduction is viewed as the first part of the manufacture of tools, and late stage reduction is viewed as the completion and maintenance of tools. Biface thinning is considered a special form of late stage reduction. For platform bearing flakes, platform facet count was determined to be the best single attribute. Dorsal scar count was determined to be the best single attribute for non-platform bearing flakes. Magne (1985:120) determined that for platform bearing flakes zero to one facets indicated early stage, two facets middle stage, and three or more facets late stage. In addition, flakes with lipped platforms and three or more facets were the result of biface thinning. For non-platform flakes, zero to one scars indicated early stage reduction, two scars middle stage, and three or more scars late stage.
The difference between Magne’s approach and typological approaches is that Magne’s stage classes are explicitly defined and represent mutually exclusive classes. An independent assessment of Magne’s stage classification scheme (Bradbury and Carr 1995) produced similar results to those reported by Magne.
Based on the tool needs of prehistoric populations, different proportions of the reduction stages are expected to be represented at a site depending on various aspects of technological organization, raw material availability and quality, and how the site was used (see Magne 1989: Figure 1 for a useful heuristic device). The reduction stage classification can be used in conjunction with the tool classes represented and other artifact analyses to better understand site use and assemblage formation. Separating the various raw materials recovered within an assemblage into the reduction stages can be used to infer how each played a role in the organization of technology.