A comparative analysis of bipolar and freehand experimental knapping products from Olduvai Gorge, Tanzania

This study aims to investigate the quantitative and qualitative differences between freehand and bipolar experimental knapping products of quartzite from Olduvai Gorge, Tanzania. A series of blind analyses are undertaken in order to better understand the effect that Olduvai quartzite may have on both inter-analyst variation and analyst accuracy in the identification of bipolar knapping products. This is followed by a comprehensive analysis of the morphology of experimental freehand and bipolar flakes and cores incorporating both traditional linear measurements as well as 2D geometric morphometric analysis; additionally, the validity of qualitative bipolar attributes are assessed in the differentiation between knapping techniques. The results of this study highlight the analytical difficulties and the high levels of analyst subjectivity in identifying bipolar knapping in Olduvai quartzite assemblages. Additionally, it is noted that the majority of morphometric measures of bipolar and freehand knapped products do not differ significantly and should not be used in isolation for recognition of these knapping techniques. Instead, conservative analysis of qualitative bipolar traits on cores may offer better results in the identification of knapping technique.