M.Benno Blumenthal, Michael Bell, How IRI is using RDF/OWL Technologies for both Discovery and Use Metadata M.Benno Blumenthal, Michael Bell, John del Corral, and Emily Grover-Kopec International Research Institute for Climate and Society Columbia University http://iridl.ldeo.columbia.edu/

Faceted Search Interface

RDF: framework for writing connections Triplets of Subject Property (or Predicate) Object URI’s identify things, i.e. most of the above

Datatype Properties WOA dc:title “NOAA NODC WOA01” WOA dc:description “NOAA NODC WOA01: World Ocean Atlas 2001, an atlas of objectively analyzed fields of major ocean parameters at monthly, seasonal, and annual time scales. Resolution: 1x1; Longitude: global; Latitude: global; Depth: [0 m,5500 m]; Time: [Jan,Dec]; monthly” This is what we are used to thinking about as attributes, except that the property is a URI rather than a prearranged agreement. Already this is progress.

Object Properties WOA dcterm:hasPart MONTHLY Alternatively WOA my:hasSubDataset MONTHLY my:hasSubDataset rdfs:subPropertyOf dcterm:hasPart This is important: I have locally defined a specific relationship while mapping it to a convention. When a more specific convention comes along, I can add that mapping as well.

netcdf/CF in RDF {SST a cfatt:non_coordinate_variable, SST cfatt:standard_name cf:sea_surface_temperature, SST netcdf:hasDimension longitude } Object properties provide a framework for explicitly writing down relationships between data objects/components, e.g. vague meaning of nesting is made explicit Properties also can be related, since they are objects too

Ontologies Use Conventions to connect concepts to established sets of concepts Generate additional “virtual” triples from the original set and semantics RDFS – some property/class semantics OWL – additional property/class semantics “late semantic binding”

Search Interface Items (datasets/maps) Terms Facets Taxa

Search Interface Semantic API {item} dc:title dc:description rss:link iridl:icon dcterm:isPartOf {item2} dcterm:isReplacedBy {item2} {item} trm:isDescribedBy {term} {term} a {facet} of {taxa} of {trm:Term}, {facet} a {trm:Facet}, {taxa} a {trm:Taxa}, {term} trm:directlyImplies {term2}

Ontologies Data Servers MMI JPL bibliography Start Point Standards Organizations RDF Crawler Location Canonicalizer RDFS Semantics Owl Semantics SWRL Rules SeRQL CONSTRUCT Time Canonicalizer Sesame Search Queries Search Interface

Maproom Search: Humidity

Maproom Search: precipitation

In a more perfect world Conventions would have RDF/OWL ontologies expressing them Metadata transport mechanisms would carry explicit properties between their data objects/components, Explicitly map their properties to conventions Important not only because it provides a namespace that can be pointed to, but also because explicit object relationships may mean that the RDF representation is much simpler to understand/decode, preparing the convention for future metadata transport mechanisms