Stone Tool Debitage Fails to Reliably Identify a Toolmaker’s Handedness

Author(s): Chloe Holden; Lana Ruck; Shelby S. J. Putt

Year: 2019


This is an abstract from the "SAA 2019: General Sessions" session, at the 84th annual meeting of the Society for American Archaeology.

The classification of stone tool debitage features as right- or left-oriented has become an increasingly common method for assessing knapper handedness in experimental and archaeological lithic assemblages. Replication attempts using these published methodologies, however, have been unsuccessful. We tested the validity of eight flake feature categories, from Bargallo et al. (2017) and and Dominguez-Ballestros & Arrizabalaga (2015), assessing their predictive accuracy with an inter-rater reliability analysis on an experimental assemblage of Oldowan flakes produced by 18 knappers (9 left-handed). Three experienced raters independently made blind predictions of knapper handedness using directional skew for each of the eight features, on 344 complete flakes from 43 isolated knapping events. Inter-rater reliability measures (Fleiss’ Kappa) showed fair agreement for only two flake features (eraillure scar and impact point locations), with moderate (hackles, ripples, parabolic crack) to poor (ridge, extraction axis, platform inclination) agreement for all other features. All three raters failed to perform significantly better than chance for predicting handedness. These results suggest not only that these flake features are unreliable predictors of a knapper’s handedness, but also, that some of these features do not represent objective categories. We therefore urge caution in applying this method to archaeological assemblages pending further independent replication.

Cite this Record

Stone Tool Debitage Fails to Reliably Identify a Toolmaker’s Handedness. Chloe Holden, Lana Ruck, Shelby S. J. Putt. Presented at The 84th Annual Meeting of the Society for American Archaeology, Albuquerque, NM. 2019 ( tDAR id: 450126)

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Spatial Coverage

min long: 24.082; min lat: -26.746 ; max long: 56.777; max lat: 17.309 ;

Record Identifiers

Abstract Id(s): 24699