From the website (the bold font is mine):

The project will use an innovative new approach to data management in order to bring together the many separate sources of information that we have about ports in the Roman Mediterranean. The Semantic Web is a way of linking data by storing it as statements rather than in tables. Because the statements are composed of the same URIs that you use in the address bar of an internet browser, they can be accessed by other computers so different datasets can be connected together more easily. It also means that we can see all the information related to a given concept, whether it’s a thing, a property or a class of objects. [some interesting papers about this approach can be found here]

We hope that by using this methodology we might soon be able to ask questions such as ‘where are all the known finds of Dressel 20 amphorae on the Mediterranean coast?’, or ‘which other towns have used the same types of marble as those employed in Tarragona?’ It is with this kind of knowledge that we can start building theoretical networks of trade and mobility.