The theoretical model is based on the E/R model, but it extends it with new properties to represent the scenario. In the model one can see the aligned terms described in the prior section “Metadata standard alignment”.

Specifically, the theoretical model must answer the following questions:

WHO – people. How to describe people? Which kind of information?

WHERE – places. With which kind of information do I have to represent locations?

WHEN – dates. In which format do I need to express the notion of time?

WHAT – subjects/concepts. What is the main content of my objects?