This course provides an introduction to biomedical ontology. It will review how data and information are generated through biological and biomedical experiments and through patient care, and show how ontologies are used in accessing, maintaining, and exploiting the results. We will describe how biomedical ontologies are developed and evaluated and provide a comparative critical analysis of the principal current ontology resources. We will also review the major theories, methods, and tools for the development of ontologies, and illustrate how these are being used in different areas of biomedical research and healthcare. On completion of this course students will have a thorough understanding of strategies to manage and exploit biomedical data; they will have a knowledge of categorization, of the philosophy of experimentation, of the philosophy of medicine, and of computer-based reasoning with data.