COMMENT: Analyst's Corner

Adding Meaning to the Digital World
By David Baum

The Semantic Web organizes and captures data relationships to enrich information exchange.

Oracle Magazine spoke with Laura Ramos, vice president of the Health Care and Life Sciences team at Forrester Research, to learn how developers make applications smarter with Semantic Web technology.

Oracle Magazine: What is the Semantic Web, and how does it differ from the Web we know today?

Ramos: The Semantic Web provides a common framework that allows data to be shared and reused across application, enterprise, and community boundaries. While the World Wide Web taught us to link pages and documents electronically, the Semantic Web lets us link smaller elements of data and information and assign meaning to the links between data elements. Semantic technology helps associate different types of information to enable much broader and richer information discovery and exchange.

Oracle Magazine: Is the Semantic Web primarily an internet phenomenon, or does it represent technologies that are useful on a corporate intranet as well?

Ramos: Right now, most Semantic Web activity is centered on the internet, but people who build and manage business applications are starting to see its value, particularly in industries that manage huge volumes of information. For example, pharmaceutical companies invent new chemical compounds, but their identifications, formulations, and names change over the five to eight years it takes to go from a patented compound to an approved, regulated medicine. Initially, a compound may be described by a number, later by a scientific chemical name, and ultimately by a commercial brand name. With the Semantic Web, a community of scientists working on new medicines set up a universal resource identifier to identify a compound and map all later instances or references back to this resource. As the name of the compound changes, researchers, toxicologists, and chemists can still find and track the drug based on its attributes and relationship to other therapeutic research, such as where the compound fits in a protein expression pathway or how it reacts when in the presence of other compounds.

Oracle Magazine: How do developers specify the relationships between data elements?

Ramos: The World Wide Web Consortium established two standards: the Resource Description Framework (RDF) and the Web Ontology Language (OWL), which define how developers specify these relationships. These standards define how data, text, and facts are linked and how to define relationships between elements. The syntax used to make semantic associations is called an RDF tripleĀ—a basic statement of the relationship between a subject or instance and an object or category. The triple definition lets information describe itself. Applications can interpret RDF triples without knowing many details about the source or schema of the data. Self-description reduces the coding and data mapping needed to exchange information between applications.

Oracle Magazine: What is a Semantic Web ontology, and how does it differ from a taxonomy?

Ramos: Ontologies capture data relationships and their associated meanings. Taxonomies are a way of referring to concepts in a hierarchical fashion, including parent/child relationships or general/specific cases (a car is a general concept; a Corvette is a specific instance of this concept). An ontology can capture hierarchies as well as more-complex definitions, relationships, and classifications: A hamburger is a type of food; a carburetor is a component of an automobile engine. It can also sort out meaning when information is subject to interpretation: "stock" as an equity, a soup base, cattle, or a part of a rifle. This embedded meaning makes it easier to define information more precisely and convey how it should be used by other applications.

Oracle Magazine: Why is a relational database important in this context?

Ramos: Storing Semantic Web relationships and metadata alongside the business information that already exists in a relational database makes sense. Oracle helps advance the Semantic Web by enabling developers to store RDF triples in Oracle Database. Supporting standards like RDF and OWL makes it easier to combine structured information, metadata, and semantic relationships in a relational store and to link to information stored in other locations. For example, an individual electronic health record might combine basic textual information about a patient, such as height, weight, and blood pressure, with complex images, such as laboratory results, X-rays, MRIs, and annotated EKGs. The Semantic Web helps system developers pull this information together into one virtual record without having to move, rename, manipulate, or map this disparate data. Developers are freed from knowing many of the details about how this information is structured or stored at its origin. We see similar examples in publishing, the automotive industry, telecommunications, and national intelligence. Although practical uses of Semantic Web technology are just emerging, each successful implementation paves the way for others to follow.


David Baum ( david@dbaumcomm.com ) is a freelance business writer based in Santa Barbara, California.

Forrester Research ( www.forrester.com ) provides advice about technology's impact on business and consumers.



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