I'm new to Semantic Web. It seems to me that Semantic Web is similar to an expert system. You can have fact, rules and queries to work with, exactly like Prolog. I feel like it's the same as the idea of expert system, except that it has add-on features to be feasible on the internet. Is Semantic Web actually an expert system on the internet? Do the ideas originate from logic and logic programming? How much knowledge of Prolog can I make use of?
asked 13 Dec '12, 04:54
The analogy with expert systems is not a bad analogy but it's also deceptive.
Expert systems typically contain 10,000 or fewer facts and tend to use powerful logics like First Order Logic.
Semantic web inference systems like RDFS and OWL are based on description logics which are less powerful than FOL but also decidable and more scalable.
Certainly people have built "expert systems" that use RDF data. For instance, Amdocs created a system which pulls customer data out of various enterprise databases to make an RDF graph (say 10k triples) and then applies a rulebox to give some hints to the customer service person about what this customer's boggle might be. There's a fairly wide range of applications where you can process many facts against a rulebox in a streaming mode and these applications share a lot with expert systems.
In the other direction there is the use of machine learning and other probabilistic methods, some of which thrive on huge amounts of data. Some systems like this confront expert systems on their own ground (a system like Amdocs could be built based on learning, not rules) and others of which are able to do very superficial "reasoning" over very wide domains.
answered 13 Dec '12, 15:49
I guess the Semantic Web is many different things to many different people. Some people see it primarily as a way to release community data from databases and apis by publishing the raw data as open rdf, some people see it primarily as a way to integrate information from disparate data sources, some people see it primarily as a way to encourage publishing structured data on the internet. Some people see it as a way of publishing expressive, self documenting vocabularies using owl/rdfs and some people see it as a way of having an internet wide expert system.
There are plenty of difficulties of having an internet scale expert system and reasoning over such a vast amount of information though :-)
I'm not sure how directly prolog influenced the Semantic Web, but SW rules and Prolog certainly have an underlying ancestry in logic.
Prolog wise - there's plenty of similarities conceptually which you've already pointed out, and there's also http://www.swi-prolog.org/web/index.html.
answered 13 Dec '12, 10:48