A Marine Platforms Ontology: Experiences and Lessons Luis Bermudez 1 , John Graybeal 1 , Robert Arko 2 1 Monterey Bay Aquarium Research Institute 700 Sandholdt Road, Moss Landing, CA, 95039 USA {bermudez, graybeal}@mbari.org 2 Lamont-Doherty Earth Observatory of Columbia University 61 Route 9W, Palisades, NY 10964 USA arko@ldeo.columbia.edu Abstract. The community-centered creation of ontologies is an essential process to increase semantic interoperation across disciplines. The Marine Metadata Interoperability Project (MMI) is keenly aware of the need for such ontologies to advance the sophisticated interaction of research communities and their data systems. This paper presents the creation of a marine platforms ontology, fostered by MMI and jointly developed by a team of data system developers from the marine science and ontological communities. Keywords: Ontology, Platform, Community, Experience, Marine, Lessons, Sensor. 1. Introduction In August 2005, the Marine Metadata Interoperability Project (hereafter MMI) [6] held a workshop [7] to coordinate the mapping of science domain vocabularies. The sensor team at the workshop determined that a comprehensive ontology of sensors used by the marine science community did not exist. However, they decided that the best starting point for the creation of such ontology was the Global Change Master Directory (GCMD [15]) instrument keywords, and the related Semantic Web for Earth and Environmental Terminology (SWEET [16]) sensor ontology, which is based on the GCMD keywords. During their work, the team found that GCMD top-level categories presented a mixture of domain and measurement types; many sensors would fit into more than one class; and there is a mixture and overlap of instruments and platforms concepts. The workshop produced an initial reformulation of the GCMD/SWEET sensors list, organizing their work according to the techniques by which the various sensors operate. This provided at least a reasonably consistent basis for categorizing the major sensor groups.