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January 18, 2012

PowerPoint Presentation

Understanding the Semantic Web: Basic Concepts and Technologies

Webex Recording of the meeting

Go here to get the webex recording player

Topics Covered

Dave Blodgett (Lead)
Janice Gordon (Presenter)
Andrew Yan
Cassandra Ladino
David Coyle
Jeanne Jones
Jennifer Carlino
Jim Kreft
Mike Stern
Peter Schweitzer
Scott ?
Scott McEwen
Tim Mancuso


Semantic Web Overview.

"Semantic Web" Web of Data Data Web Web 3.0 Linked Data Web...
Compare/contrast Generic and semantic web.
Generic Web = Document web for humans to read and understand. ex. Wikipedia.
Semantic Web = Data Web for machine understanding ex DBPedia.
Linked Data
Linked Open Data: Same as linked data but under a public license
Why Semantic Web?
Data is of greater value than documents.
Facilitates changes without changing "code lists"
Reference distributed data.
Works well with relational databases

Semantic Concepts and Use Cases
Discussion of commonality of these.
Technology stack.
Focus here is on data, ontologies and querying

RDF Resource Description Framework

For publishing and linking data.
Everything represented by URI "triple" "My dog has a name and its gus"
Playing a video:
Many of the examples based on this video.
Going through an example of RDF.

  • N-Triple
  • Turtle

a = attributes: For embedding semantic (RDF) data in a web document.
Looks at a use case: Best Buy.
Shows how semantic technologies have been incorporated into their web site.


A form of classification for terminology.
Uses the example of a music ontology.

SKOS Simple Knowledge Organization System

A standard way to represent ontologies in RDF.
Uses an example of AGROVOC, agriculural vocabulary:
Shows the SKOS encoded as RDF/XML representation of Maize

RDFS S = Schema

A schema or syntax language for RDF.
Allows creation of parent child relationships in RDF.

OWL: Web ontoogy language.

Extends RDFS to handle inference.
relationships, cardinality, typing, characteristics, enumerations.
Allows the use of reasoning engines to infer new data.
Shows example using deeper definition of "hasSibling"

SPARQL Protocol and RDF Query Language

Query language for RDF data.
Can query local data or SPARQL endpoints (web services)
Shows simple sparql example.


Shows three tiered data/semantic/application architecture.
Shows D2R server architecture that helps mix relational and semantic databases.
Uses example of BBC 2010 World Cup site as an example.
USGS standpoint, how do we move forward?
References Tim Berner-Lee's 5 star rating.

Question about publishing requirements within USGS: Probably need some changes in thinking of what it means to publish data.

Comment about the Marine Metadata Inventory: