As an alternative to stage based approaches, Ingbar et al. (1989; also see Bradbury and Carr 1999; Shott 1996) suggest modeling lithic reduction as a continuum. They argue that lithic reduction is a continuous process in which the relationship between flake attributes and the process of reduction is predictable (Bradbury and Carr 1999; Ingbar et. al. 1989; Shott 1996).
The continuum-based approach used by CRA is based on a method developed by Bradbury and Carr (1999). This form of analysis is conducted in two stages. First, individual flakes produced during core reduction are separated from those produced during tool production. This is accomplished through the use of discriminant functions developed from an experimental data set. This analysis uses only flakes exhibiting a complete platform, as metric measurements are used in the discriminant functions.
In the next stage of the analysis, all tool production debris is analyzed through the use of a regression formula that allows for the placement of the flake into the reduction sequence. This reduction sequence is represented by the use of a standardized scale where zero indicates that no reduction has taken place and one represents a completed tool. The scale provides a means of determining the percent completion of a tool when the flake was removed. Consequently, resharpening and reworking of a tool will yield values greater than one. As a check of this continuum based approach, the regression equations developed by Ingbar et al. (1989) and Shott (1996) can also be used. All calculations needed for the analysis are computed using a database program written by Mr. Bradbury.
Additional information can be gleaned from such analyses by creating histograms for each raw material type (Bradbury and Carr 1999). Such histograms should also show the trends suggested in the first step of the analysis. In addition, statistical methods (such as the Kolmogorov-Smirnov test) can be used to determine if the observed differences are significant.