"Reify" means to take an abstract idea, and to make it concrete.
In the world of RDF, it means to write RDF statements about RDF statements.
For instance, you might have a triple:
I like RDF.
To reify it, you would say:
<statement> rdf:type rdf:Statement <statement> rdf:subject <me> <statement> rdf:predicate <likes> <statement> rdf:object <RDF>
The statement is the triple (subject, predicate, object.)
The reified form of a statement is a node R that has four properties:
<R> rdf:type rdf:Statement <R> rdf:subject <subject> <R> rdf:predicate <predicate> <R> rdf:object <object>
I have read that a reified statement is a "resource" which represents a statement. I'm not quite clear of the difference between reified form and a reified statement. It seems to me that a reified statement refers to the node <R>, while reified form just refers to it's shape.
If that's the case, I'd just say: "A reified statement is a node that follows the reified form..."
Are reified nodes things that you make, or are they "automatically given to you" by your tuple store?
For example, if you loaded a normal tuple store, and then said, "give me the BlankNode that has this for the subject, this for the predicate, and this for the object, and is of rdf:type rdf:Statement,"- is the tuple store obligated to give you back a BlankNode?