The map is not the territory … The word is not the thing.
la World Wide Web Consortium ha puesto a disposición de todo er mundo mundiá un FAQ(Preguntas frecuentas) sobre Qué es la web semántica, (eso que todavía nadie se ha enterado de lo que era la Web 2.0, ese concepto un poco….basta con las citas de arriba). Os copio-pego el punto 1 .
1. What is the Semantic Web?
The vision of the Semantic Web is to extend principles of the Web from documents to data. This extension will allow to fulfill more of the Web’s potential, in that it will allow data to be shared effectively by wider communities, and to be processed automatically by tools as well as manually.
The Semantic Web allows two things.
- It allows data to be surfaced in the form of real data, so that a program doesn’t have to strip the formatting and pictures and ads off a Web page and guess where the data on it is.
- it allows people to write (or generate) files which explain—to a machine—the relationship between different sets of data. For example, one is able to make a “semantic link” between a database with a “zip-code” column and a form with a “zip” field that they actually mean the same – they are the same abstract concept. This allows machines to follow links and hence automatically integrate data from many different sources.
Semantic Web technologies can be used in a variety of application areas; for example: in data integration, whereby data in various locations and various formats can be integrated in one, seamless application; in resource discovery and classification to provide better, domain specific search engine capabilities; in cataloging for describing the content and content relationships available at a particular Web site, page, or digital library; by intelligent software agents to facilitate knowledge sharing and exchange; in content rating; in describing collections of pages that represent a single logical “document”; for describing intellectual property rights of Web pages (see, eg, the Creative Commons), and in many others.
In order to achieve the goals described above, the most important is to be able to define and describe the relations among data (i.e., resources) on the Web. This is not unlike the usage of hyperlinks on the current Web that connect the current page with another one: the hyperlinks defines a relationship between the current page and the target. One major difference is that, on the Semantic Web, such relationships can be established between any two resources, there is no notion of “current” page. Another major difference is that the relationship (i.e, the link) itself is named, whereas the link used by a human on the (traditional) Web is not and their role is deduced by the human reader. The definition of those relations allow for a better and automatic interchange of data. RDF, which is one of the fundamental building blocks of the Semantic Web, gives a formal definition for that interchange.
On that basis, additional building blocks are built around this central notion. Some examples are:
- Tools to query information described through such relationships (eg, SPARQL)
- Tools to have a finer and more detailed classification and characterization of those relationships. This ensures interoperability and more complex automatic behaviors. For example, a community can agree what name to use for a relationship connecting a page to one’s calendar; this name can then be used by a large number of users and applications without the necessity to redefine such names every time. (E.g., RDF Schemas, OWL, SKOS)
- For more complex cases, tools are available to define logical relationships among resources and the relationships (for example, if a relationships binds a person to his/her email address, it is feasible to declare that the email address is unique, ie, the address is not shared by several persons). (E.g., OWL, Rules)
- Tools to extract from, and to bind to traditional data sources to ensure their interchange with data from other sources. (E.g., GRDDL, RDFa)
It is difficult to predict what a “killer application” is for a specific technology, and the prediction is often erroneous. That said, the integration of currently unbound and independent “silos” of data in a coherent application is certainly a good candidate. Specific examples are currently explored in areas like Health Care and Life Sciences, Public Administration, Engineering, etc.
Not necessarily, at least not directly. The Semantic Web technologies may act behind the scenes, resulting in a better user experience, rather than directly influencing the “look” on the browser. This is already happening: there are Web Sites (e.g., Sun’s white paper collection site, or Nokia’s support portal for their S60 series device, Oracle’s virtual press room, Harper’s online magazine) that use Semantic Web technologies in the background.
As all innovative technologies, the Semantic Web underwent an evolution starting at research labs, being then picked up by the Open Source community, then by small and specialized startups and finally by business in general. Remember: the Web was originally developed in a High Energy Physics center!
At present, the Semantic Web is increasingly used by small and large business. Oracle, IBM, Adobe, Software AG, or Northrop Grumman are only some of the large corporations that have picked up this technology already and are selling tools as well as complete business solutions. Large application areas, like the Health Care and Life Sciences, look at the data integration possibilities of the Semantic Web as one of the technologies that might offer significant help in solving their R&D problems.
First of all, as pointed out elsewhere in this document, one can develop Semantic Web applications without using ontologies. Very useful applications can be built without those, relying on the most fundamental, and simple concept of the Semantic Web. However, even if ontologies, rules, reasoners, etc, are used, the average user should not care about the complexities of, say, the details of reasoning. All this is done “under the hood”. What the developer needs to operate with are usually simple logical patterns of the sort “Given that
(Flipper isA Dolphin) and
(Dolphin isAlso Mammal), one can conclude that
(Flipper isA Mammal)“.
Compare it to SQL. The official SQL standards, the formal semantics of SQL, and indeed its implementations are extremely complex and understood by a few specialists only. Nevertheless, a large number of users use SQL in practice, without caring about the underlying complexities.
The Semantic Web is an extension of the current Web and not its replacement. Islands of RDF and possibly related ontologies can be developed incrementally. Major application areas (like Health Care and Life Sciences) may choose to “locally” adopt Semantic Web technologies, and this can then spread over the Web in general. In other words, one should not think in terms of “rebuilding” the Web.
Fuente: [w3org, vía Barrapunto]