Distinguishing stone age drilling techniques on ostrich eggshell beads: An experimental approach

In this article we outline a statistical method for distinguishing ostrich eggshell (OES) beads perforated with a hand turned drill bit and those created with a hafted drill. This distinction has important implications for tracking past bead-making traditions across space and time, and for tracing the first appearance and spread of hafted drilling. Previous efforts to reconstruct the way in which beads were perforated have relied on a common sense approach, usually in combination with an experimental reference. However, without blind-test results or other metrics of reliability it is unclear how accurate these methods are. We argue that the quantitative framework described here provides a much needed answer to this question and helps to further systematize the process of bead analysis. We also define a set of terms which we hope will allow for a more standardized discussion of bead production signatures and techniques.