RDFS and OWL Reasoning for Linked Data - Reasoning Web - page 113

Tabl e 4. Top ten ranked documents

№ Document URI Rank

1 http://www.w3.org/1999/02/22-rdf-syntax-ns 0.121

2 http://www.w3.org/2000/01/rdf-schema 0.110

3 http://dublincore.org/2010/10/11/dcelements.rdf 0.096

4 http://www.w3.org/2002/07/owl 0.078

5 http://www.w3.org/2000/01/rdf-schema-more 0.049

6 http://dublincore.org/2010/10/11/dcterms.rdf 0.036

7 http://www.w3.org/2009/08/skos-reference/skos.rdf 0.026

8 http://xmlns.com/foaf/spec/ 0.023

9 http://dublincore.org/DCMI.rdf 0.021

10 http://www.w3.org/2003/g/data-view 0.017

mentioned in the previous section, as well as support for the features in various
RDFS/OWL profiles. Those titled EL , QL and RL refer intuitively to the standard
OWL 2 profiles [25]. The RDFS standard is titled RDFS . All other profiles are
non-standard proposals made in the literature. The profile titled RDFS+ refers
to RDFS-Plus as proposed by Allemang and Hendler [1], which extends RDFS
with lightweight OWL features. The profile titled L2 refers to a similar proposal
by Fisher et al. [20] to extend RDFS with some lightweight OWL features.
Description Logic Programs (DLP) was proposed by Grosof et al. [26] in order
to support incomplete OWL reasoning using rules; this proposal was later built
upon in Horst's pD* profile [65]. The AL profile refers to features that can be
supported with rules that do not requires A-Box (i.e., assertional joins), which
are expensive to compute at scale; the AL profile is used later in Section 5.
In column '

', we indicate which features have expressions that can be rep-
resented as a single triple in RDF, i.e., which features do not require auxiliary
blank nodes of the form :x or the SEQ production in Table 1 of the OWL 2
Mapping to RDF document [56]. This distinction is motivated by our initial
observations that such features are typically the most widely used in Web data.
From the list of language features, we exclude rdf:type , which trivially ap-
peared in 90.3% of documents. We present the table ordered by the sum of
PageRank measure [ Rank

ST

].
Regarding prevalence , we see from Table 5 that owl:sameAs is the most widely
used axiom in terms of documents (1.778 million; 24%) and domains (117;
14.8%). Surprisingly (to us), RDF container membership properties ( rdf: * )
are also heavily used (likely attributable to RSS 1.0 documents). Regarding
prominence , we make the following observations:

1. The top six features are those that form the core of RDFS [53].
2. The RDF(S) declaration classes rdfs:Class , rdf:Property are used in
fewer, but more prominent documents than OWL's versions owl:Class ,
owl:DatatypeProperty , owl:ObjectProperty .