The effect of raw material on inter-analyst variation and analyst accuracy for lithic analysis: a case study from Olduvai Gorge

This study aims to understand what effect, in terms of inter-analysis variation and analyst accuracy, different raw material types have on modern technological analyses of lithic assemblages. This is done through a series of blind analysis tests undertaken on experimentally derived assemblages of cores and flakes. Novelties of our approach include the introduction of refit studies as a method to assess analyst's accuracy, and the use of statistical tests specifically designed to address inter-analyst variability, common in other disciplines but rarely used in Archaeology. The experimental assemblages were produced from raw materials collected at Olduvai Gorge, an archaeological sequence that has been a source for studies of early human technology for several decades, and where re-analyses of the same assemblages have usually offered different interpretations. The results of the blind analyses are compared to the true technological values obtained through full refit analysis of the experimental material, and suggest that there is a significant difference in terms of inter-analyst variability as well as accuracy related to different raw materials. Our paper highlights the interpretative problems posed by difficult-to-analyse raw materials such as quartzite, and stresses subjectivity present in stone-tool technological studies, which may contribute to explain differences in the interpretation of Early Stone Age lithic assemblages. (C) 2014 Elsevier Ltd. All rights reserved.