Reliability and validity in determining the relative chronology between neighbouring scars on flint artefacts

Abstract

We aimed to experimentally test the credibility of the diacritic analysis, which is one of the methods used to study lithic knapping technology. A series of blind tests conducted by lithic experts and students on experimentally knapped artefacts were used to estimate the reliability and validity of the method. The estimated average error rate was 21%, although it was smaller among the experts in the method (15%) and higher (25%) for the beginners. Further analyses indicated that the errors were not made randomly but concentrated in challenging spots. We additionally tested several factors that might influence the difficulty of identifying the scar chronology and, therefore, suggested a set of actions that can prevent errors when determining the relative chronology of scars on lithic artefacts.