My research interests are in Knowledge Representation and Reasoning, where I am best know for research on Description Logics, which are today the foundation of Web Ontology Languages (OWL), and Ontology-Based Data Access (OBDA). I have applied KRR techniques to Databases and Software Requirements and Specification. In turn, these raised KRR issues that led me to new problems. I obtained my PhD in theoretical computational linguistics from the University of Toronto, where my supervisor was C. Raymond Perrault. I travelled around the world for a year, and then switched to work on something more applied: conceptual modeling based on KR languages.