Helping people (and machines) understanding each other: The role of formal ontology

In scientific communication, we usually resort to formal theories - like algebra or first-order logic - to express our thoughts and intuitions in such a way they can be understood by our colleagues. I will argue that the tools of formal ontology (such as the notions of parthood, unity, dependence, identity) can play a similar role in ordinary communication, for instance during e-commerce transactions. I will briefly present what these tools are, and I will give examples concerning their role in facilitating mutual agreement, as well as recognizing and explaining disagreement.