Future Wave Web Technology Blog

This video con­tin­ues an intro­duc­tion to the Semantic Web.  The idea of how data is stored in the Semantic Web frame­work was com­pared to the rela­tional data­base model.  The con­cept of ‘open-data’ was intro­duced. In an open-data model, the data is exposed as part of a global data­base, in a stan­dard­ized way so that it can be com­bined with other data (infor­ma­tion) and shared. The tra­di­tional rela­tional data­base model embed­ded the mean­ing and the rela­tion­ships in the soft­ware that runs on the server. You would have to know how the data­base was struc­tured on any par­tic­u­lar domain or web­site before you could use that data or information/knowledge. There was no stan­dard way of encod­ing the mean­ing or the struc­ture of the data­base. This meant that you had islands or silos of data or infor­ma­tion and one web­site could not ask or use data that was on another web­site — unless a par­tic­u­lar web­site hap­pened to pub­lish a way to inter­face with that data­base. Obviously no one is going to learn about how each of the mil­lions of web­sites that have rela­tional data­base back-ends are expos­ing their data.

The solu­tion is to have a stan­dard way of rep­re­sent­ing knowl­edge, data or infor­ma­tion. This is the Resource Descriptive Framework (RDF). RDF allows for express­ing explicit knowl­edge or explicit state­ments — later we will learn about how to infer more knowl­edge beyond what is explic­itly stated. The RDF rep­re­sents knowl­edge, infor­ma­tion or asser­tions in the form of triples — Subject Predicate Object. This might be thought of in the same way as sub­ject verb object, but that doesn’t fit in all instances. I might say “Bruce knows Jean.” That is a triple and it rep­re­sents an explicit state­ment. Subject is Bruce, pred­i­cate is knows and object is Jean. I might also say “Person1 has­First­Name Bruce” and “Person1 hasLast­Name Whealton.” This is a way of express­ing using two triples, two facts about me. I have a first name of Bruce and in the next state­ment, I state that I have a last name of Whealton.

This can also be rep­re­sented in a graph for­mat using ellipses and arrows.

---

This blog is pub­lished by Bruce Whealton, more infor­ma­tion about Bruce Whealton is here… Bruce Whealton is the owner of Future Wave Designs, a North Carolina Company pro­vid­ing Web Design and Web Development. Visit:
NC Web Design:Future Wave Designs

---

Technorati Tags: rdf, RDFa, seman­tic web