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This is slightly Off-topic!!!. But please answer to this question. I have studied lots of articles and materials on net about RDF but i can't understand one thing is how programatically subject, predicate and object is dividing in a natural English line.

Ex: Scott Directed Runner.

If i give this above line, then how the above line is divided into subject,predicate and object with respect to programmatical. please answer.

Thx...

Joshua Taylor
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user3524423
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    I'm not sure yet whether this is off topic or not, but I'm not sure either exactly what you're asking. RDF is about representing directed graphs with labeled edges. It happens that many types of data can be represented very nicely in this way. Because it's such a free form representation, though, it means that it's important to define *how* you use RDF to represent a given domain. There are lots of ways that you could represent natural language texts using RDF, but there's no canonical "right" way to do it. – Joshua Taylor Apr 21 '14 at 15:51

1 Answers1

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subject, predicate, and object, are used in NLP to define aspects of sentences in some languages, as you mentioned. Do not conflate that with their usage in this context. In RDF, they are names for three distinguishing characteristics of a triple/statement.

Read RDF1.1 Concepts and Abstract Syntax and note that one major takeaway is that a statement is formally defined as a 3-tuple (triple) consisting of:

  • subject:= the node the statement/edge starts at
  • predicate := a semantically important label for for the statement/edge
  • object := the node that the statement/edge terminates at

As you learn more about RDF, you'll learn that you have two major problems:

  1. The Pure NLP problem that you have asked earlier, consisting of "How does one map a sentence in a natural language to a statement in RDF". This is not a trivial task, and requires that one study a great deal of NLP in order to solve.

  2. The RDF problem, which will be "what should I define as my representation for this content once I know what I am extracting". This will include direct mapping of language expressions ("bob is a cat" -> :bob rdf:type :Cat) and mapping of more arbitrary concepts

An example of mapping a more arbitrary concept: "All cats have at least one owner" -> 

:Cat rdfs:subClassOf _:x .
_:x rdf:type owl:Restriction .
_:x owl:onProperty :hasOwner .
_:x owl:minCardinality "1"^^xsd:nonNegativeInteger .

To risk understating the point, the general problem that you have formulated is an extraordinarily large task that may not be well suited to StackOverflow. You will need to break this task up into many many much smaller issues while you develop an understanding of the domain, and then ask specific technical questions as you work on this.

Rob Hall
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