Standardisation and units of measurement used in pottery production

The standardisation or diversity of ceramic productions is one type of evidence provided by the archaeological record that allows researchers to form hypotheses regarding pottery artisan specialization. In addition to this evidence, the study of ancient ceramics can also provide information about production structures, processing techniques, and scales of production.
The aim of this paper is to determine the degree of standardisation of a pottery production and units of measure that regulated or determined their production. The group chosen to test the methodology has been known as Spanish Olive jar. It is a series of productions manufactured in the south of the Iberian Peninsula throughout the Modern Age. The methodology starts from the morphometric characterisation of each vessel around a series of quantitative variables. As previous steps to the rest of the analysis the Test for normality is performed and the product-moment correlation coefficient is calculated. Subsequently, different groups of Spanish olive jar are created through the cluster analysis. The principal component analysis provides information that allows a deeper understanding of the groups obtained. On the other hand, the coefficient of variation allows to know the degree of standardisation of each variable. Finally, once all these data are known, the possible units of measure that governed the production system of the Spanish olive jar may be recognised.