The Spoil project. Assessing the rate of excavators’ accidental ceramic discard at the archaeological site of Siponto

This article aims to quantify the rate of accidental ceramic discard on the archaeological site of Siponto (Italy), where in 2022 the University of Bari and the University of Foggia conducted fieldwork and training for students at different education levels (BA to PhD). The goal was to identify and quantify factors leading to the accidental discard of ceramic sherds by excavators on the spoil heap. As a pilot project, a few variables have been considered to count the minimum number of individuals found after sieving soil composition and colour, weather conditions, time variables, sherds size, colour, and vessel part. Other categorical or presence/absence variables have also been considered. This enlightening investigation shows the bias in post-excavation quantification of ceramic finds. Results indicate that 30% of the fragments of pottery retrieved from the spoil heaps, used in this experiment, were diagnostic. The study also helps the educators on-site to identify the types of vessels that might be less clear for the students.