He is also affiliated with the Division of Preventive Medicine of Brigham and Women’s Hospital at the Harvard Medical School. His primary research area is formal ontologies, and he has been actively working in the area of biomedical ontologies since 1992. Prof. Baclawski has been active in the development of the Semantic Web since it was first proposed, being part of the team that developed the DAML+OIL language, later renamed the Web Ontology Language (OWL).