Ontologies and the Semantic Web - An Introduction for Non-Experts
What is an ontology? As a geoscientist/researcher/data manager what can Semantic Technologies do for me?
This tutorial and introductory session takes attendees through the process of defining what an ontology is, where to find them, and what the collection of Semantic Technologies can do for the geosciences. We will explore what tools and semantic models are currently available, where to find them, and what one might do with them once they're found. Examples of existing and diverse geoscience sematic applications will be presented and demoed. We will also explore new application and collaboration areas within ESIP as well as explore potential limitations of such technologies.
Ontologies and the Semantic Web - An introduction for non-experts
Moderator: Tom Narock, UMBC
ESIP working group - Semantic Web & Semantic Technologies
-Recently promoted to a committee
Promoting, looking for new application areas, get an idea of how the community is using this technology
Today: introduce the technology, get an idea of how it’s being used, feedback
Crowd in attendance is entirely novices - new users or folks who really know nothing about Semantic Web
1. Carlos Rueda - Monterey Bay Aquarium Research Institute
Semantic Web: Core Concepts and Mechanisms
MMI ORR - Ontology Registry and Repository
-Semantic Web is all about formally capturing knowledge about the world so computers can be more useful, and so we can tackle pressing problems more effectively and efficiently
-knowledge in forms of triples: subject - predicate - object (e.g. Calvin - has friend - Hobbes)
-RDF: Resource Description Framework
-W3C standard to express information about resources
-anything can be a resource, including physical things, documents, abstract concepts, numbers, and strings
-the triple components denote resources
→ designed to support the Semantic Web (similar to how html supports the Web)
-AAA: “anyone can say anything about anything”
-RDF-based applications must find ways to deal with conflicting sources of information
-Resources are denoted by IRIs or literals
-IRI: Internationalized Resource Identifier
-Literals denote values according to known datatypes (objects are literals or IRIs, predicates and subjects are IRIs)
-Map network of triples as knowledge is added to the system
-Vocabularies (= ontologies, basically)
-should be controlled:
-with names agreed upon by the community
-to reduce discrepancies
-to facilitate data discovery, reuse, integration
-to enable crosswalks/mappings
-is short, to promote and facilitate interoperability
-TRY to find existing vocabularies that are relevant to your work
-try to map your vocabularies to existing vocabularies to facilitate interoperability
-in practice: the ORR
-repository of controlled vocabs and term mappings
-web resolvable identifiers for ontologies and terms
-open world assumption: if you query the graph and nothing is found, it’s unknown (don’t assume that it doesn’t exist)
2. Tyler Stevens, Wyle Information Systems, NASA Global Change Master Directory (GCMD)
Introduction to GCMD Keywords
-hierarchical set of controlled keywords covering the Earth science disciplines
-established more than 20 years ago; since then there have been several iterations, expanded, more intricate ontologies developed, etc.
Development of keywords
-anyone in the community can suggest keywords; largely driven by the experts in science communities → goes through triage, impact assessments, check set of keyword requirements
-can make suggestions at Keyword Community Forum
3. Xiaogang (Marshall) Ma, Tetherless World Constellation, Rensselaer Polytechnic Inst.
Expressivity and Reasoning: Examples in geologic time and mineral observation
-interval (pd of time between two events) vs. instant (specific event/point in time)
-geologic time scale: ordinal hierarchical structure
-showed examples about how to use expressivity and reasoning of inference in detailed applications (e.g. geologic time, etc.)