Simple example of reification in RDF

"Tolkien wrote Lord of the Rings" can be expressed as a simple statement (subject, predicate, object) like this:

:Tolkien :wrote :LordOfTheRings .

By the way, this is using the Turtle notation for RDF. There are tools online for converting it to RDF/XML.

Using reification, you can have a separate resource representing a statement so you can state additional things about the statement itself, like "Wikipedia said that":

@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
_:x rdf:type rdf:Statement .
_:x rdf:subject :Tolkien .
_:x rdf:predicate :wrote .
_:x rdf:object :LordOfTheRings .
_:x :said :Wikipedia .

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In real life, you would want to use shared vocabularies, so that whoever or whatever is consuming the RDF will know that you are talking about that Tolkien and that LOTR:

http://dbpedia.org/resource/The_Lord_of_the_Rings
http://dbpedia.org/property/author
http://dbpedia.org/resource/dbppedia/J._R._R._Tolkien

A better way of doing it, is to use the singleton property approach.

For example, you create a singleton property to represent this statement as:

Tolkien wrote#1 "Lord of the rings" .

wrote#1 rdf:singletonPropertyOf wrote .

wrote#1 asserted_by Wikipedia .

You may want to read more about it in the paper "Don't like RDF Reification? Making statements about statements using singleton property" or its slides at http://www.slideshare.net/ntkimvinh7/www2014-singleton-propertyfinal...