Annotated RDF is an extension of RDF that builds upon annotated logic. In aRDF, you can start with any partial ordered set that you like as long as it has a bottom element. In essence an aRDF triple consists of an ordinary RDF triple together with an annotation.
We assume the existence of a partially ordered finite set (A,≤) where elements of A are called annotations and ≤ is a partial ordering
on A. We assume A has a bottom element.
For example we could have any of the following scenarios:
 A_{fuzzy} may be the set of all real numbers in the closed interval [0,1] with the usual "less than or equals" ordering on it.
 A_{time}=N could be the set of all nonnegative integers with the usual "less than or equals" ordering on it.
 A_{pedigree} could be an enumerated set of sources with a partial ordering on them. If s_{1},s_{2} ∈ A_{pedigree}then then we could think of s_{1} < s_{2} to mean that s_{2} has "better" pedigree than s_{1}.
A_{fuzzy} and A_{time} are complete lattices. Let us suppose that (A,≤) is an arbitrary but fixed partially ordered set. We also assume the existence of some aribitrary but fixed set R of resource names,
a set P of property names, and a set dom(p) of values associated with any property name p.
An annotatedRDFontology (aRDF) is a finite set of triples (r,p:a,v) where r is a resource name, p is a property name, a ∈ A and v is a value. This representation supports also RDF Schema triples such as:
 (A,rdf:subClassOf,B) indicates a subclass relationship between classes.
 (X,rdf:type,C) indicates that a resource X is an instance of some class C.
 (p,rdf:subPropertyOf,q) denotes a subproperty relation between p,q in P.
People
Octavian Udrea, Diego Reforgiato Recupero, V.S. Subrahmanian
Publications
 Octavian Udrea, Diego Reforgiato Recupero, and V. S. Subrahmanian. Annotated RDF. In the Proceedings of the 2006 European Semantic Web Conference, pages 487–501. [PDF]
 Octavian Udrea, Diego Reforgiato Recupero, and V. S. Subrahmanian. Annotated RDF (extended version). Submitted to ACM Transactions on Computational Logic. [PDF]
 Octavian Udrea, V. S. Subrahmanian, and Zoran Majkic. Probabilistic RDF. In IEEE IRI, pages 172–177, 2006 [PDF].
Presentations
 Annotated RDF presented at the 2006 ESWC [PPT]
 Probabilistic RDF presented at the 2006 IEEE IRI [PPT]
