Expediting and standardizing stone artifact refitting using a computerized suitability model

Stone artifact refitting is a valuable aspect of archaeological research and can inform on a variety of issues, such as prehistoric technology, site taphonomy, and assemblage patterning and function. It offers a means of teasing apart sites with complicated occupational histories and is particularly useful in interpreting surface lithic scatters, the dominant site type across much of the globe. Unfortunately, refitting is also labor intensive and time-consuming, especially for the inexperienced refitting analyst, making it logistically challenging in the case of many research projects. A possible solution is proposed by which the process of refitting might be partially automated. A multivariate suitability model was created in a Geographic Information Systems (GIS) environment. The refitting suitability model first eliminates low probability refits, and then ranks the remaining artifacts according to a score that reflects their likelihood of refitting to a target artifact. Scores are assigned to assemblage items based on a series of criteria, including raw material, cortex, size, and spatial proximity. In this pilot study, known refits from 5GN149, a surface lithic scatter in Colorado, USA, were used to test the accuracy of the model. The refitting suitability model correctly placed the known refit at the top of the list of potential refits (i.e., assigned a rank to the known refit ranging from 1 to 10) approximately 32% of the time. This is more refit identifications than would be expected through a process of pair-wise comparisons. Preliminary results suggest that the model has the potential to standardize and expedite the process of refitting.