Feasibility and Reliability of Ammer–Coelho Computational Tool for Sex Estimation: A Pilot Study on an Elderly Scottish Sample

Background/Objectives: Estimating the sex from unknown individuals is a critical step when constructing their biological profile. The distal humerus is a useful sex discriminator as shown through metric, morphoscopic, and geometric morphometric approaches. A recently developed web application using geometric morphometric techniques has provided an accessible tool for estimating sex from the shape of the olecranon fossa. The aims of this study were to examine the accuracy of the Ammer–Coelho web application on Scottish individuals, as well as test its repeatability and reproducibility among seven different observers. Methods: The right humerus was obtained from 52 Scottish individuals, and the Ammer–Coelho web application was used to estimate sex. Total accuracy rates and sex-specific rates were calculated, and an analysis of Cohen’s and Fleiss’ kappa was performed. Results: The results demonstrate an overall accuracy of 69.23% with a sex bias of −5.33%, with 55.56% of the sample being accurately estimated with probabilities equal to or higher than 0.95. Substantial agreement was reported for intra-observer error, and an overall low agreement was reported for inter-observer error Conclusions: This is the first study that evaluates the Ammer–Coelho web application. A tendency to perceive more triangular shapes (male appearance) rather than oval shapes (female appearance) resulted in a high level of observer errors, with only 6% of females correctly estimated across the seven observers. The low accuracy rates obtained could also indicate inter-population variation, as shown by other studies. Due to the results obtained, research considering different levels of observers’ experience and diverse population samples is needed to confirm our findings.