Also, this request has been updated given decisions about rdf:PlainLiteral and shortnames, and the sections on Implementations and Patents have been added.
This is a transition request, and also serves as an agenda for a Transition Meeting with the Director.
We propose to publish the following documents as Candidate Recommendation:
|owl2-syntax||OWL 2 Web Ontology Language: Structural Specification and Functional-Style Syntax|
|owl2-mapping-to-rdf||OWL 2 Web Ontology Language: Mapping to RDF Graphs|
|owl2-direct-semantics||OWL 2 Web Ontology Language: Direct Semantics|
|owl2-rdf-based-semantics||OWL 2 Web Ontology Language: RDF-Based Semantics|
|owl2-conformance||OWL 2 Web Ontology Language: Conformance|
|owl2-profiles||OWL 2 Web Ontology Language: Profiles|
|owl2-xml-serialization||OWL 2 Web Ontology Language: XML Serialization|
|rdf-plain-literal||rdf:PlainLiteral: A Datatype for RDF Plain Literals|
The estimated publication date is 11 June. (We would like to publish before the Semantic Technologies conference beginning 15 June.) At the same time, several other pre-CR OWL documents will be published, for a total of 14 documents.
2 Abstracts and Status Sections
For each document (except rdf-plain-literal), the abstract begins with a standard part:
The OWL 2 Web Ontology Language, informally OWL 2, is an ontology language for the Semantic Web with formally defined meaning. OWL 2 ontologies provide classes, properties, individuals, and data values and are stored as Semantic Web documents. OWL 2 ontologies can be used along with information written in RDF, and OWL 2 ontologies themselves are primarily exchanged as RDF documents. The OWL 2 Document Overview describes the overall state of OWL 2, and should be read before other OWL 2 documents.
This is followed by a short paragraph specific to the document in question, namely:
|Document||Second Part of Abstract|
|Structural Specification and Functional-Style Syntax||The meaningful constructs provided by OWL 2 are defined in terms of their structure. As well, a functional-style syntax is defined for these constructs, with examples and informal descriptions. One can reason with OWL 2 ontologies under either the RDF-Based Semantics [OWL 2 RDF-Based Semantics] or the Direct Semantics [OWL 2 Direct Semantics]. If certain restrictions on OWL 2 ontologies are satisfied and the ontology is in OWL 2 DL, reasoning under the Direct Semantics can be implemented using techniques well known in the literature.|
|Mapping to RDF Graphs||This document defines the mapping of OWL 2 ontologies into RDF graphs, and vice versa.|
|Direct Semantics||This document provides the direct model-theoretic semantics for OWL 2, which is compatible with the description logic SROIQ. Furthermore, this document defines the most common inference problems for OWL 2.|
|RDF-Based Semantics||This document defines the RDF-compatible model-theoretic semantics of OWL 2.|
|Conformance||This document describes the conditions that OWL 2 tools must satisfy in order to be conformant with the language specification. It also presents a common format for OWL 2 test cases that both illustrate the features of the language and can be used for testing conformance.|
|Profiles||This document provides a specification of several profiles of OWL 2 which can be more simply and/or efficiently implemented. In logic, profiles are often called fragments. Most profiles are defined by placing restrictions on the structure of OWL 2 ontologies. These restrictions have been specified by modifying the productions of the functional-style syntax.|
|XML Serialization||This document specifies an XML serialization for OWL 2 that mirrors its structural specification. An XML schema defines this syntax and is available as a separate document, as well as being included here.|
The abstract for rdf:PlainLiteral is simply: This document presents the specification of a primitive datatype for the plain literals of RDF.
The Status sections are assembled automatically from maturity-specific and working-group specific boilerplate, along with this information about changes since the last publication:
The final product can be viewed as an editor's (publication preview) draft. A set of these drafts is linked from here:
3 Decision to Request CR
For first seven (all but rdf:PlainLiteral)
For the rdf:PlainLiteral:
4 Change since Last Call
See Summary of Changes:
(This text also appears in the SOTD section of each document.)
These are all of a minor nature and would not invalidate earlier reviews.
5 Satisfies Group's Requirements
The requirements have not changed since the previous transition. None of the many reviews have claimed that the documents fail to satisfy the group's requirements.
The charter deliverables are by the group's publications, along with the test suite website.
The specification has normative references to the following W3C specifications that are not yet Proposed Recommendations:
- W3C XML Schema Definition Language (XSD) 1.1 Part 2: Datatypes currently a Candidate Recommendation.
The only group with a known dependency on OWL 2, at this time, is RIF-WG, which is currently not yet at CR.
7 Received Wide Review
See list of Last Call comments :
More than 90 comments were received in response to the publication of the Last Call Working Drafts. These included reviews from other W3C Working and Interest Groups, W3C member organizations, and numerous companies.
8 Issues Formally Addressed
The latter includes a summary of the issues raised during the two Last Call rounds.
To date, there have been two objections, one from inside the Working Group, and one from a former participant.
9.1 Alan Ruttenberg
The first was made by Alan Ruttenberg, a co-chair of the group, on behalf of his employer, Science Commons. This objection concerns whether certain primitive datatypes are considered in OWL 2 to have disjoint or unified value spaces. For example, is the floating point number 1.0 supposed to be considered the same entity as the integer 1? The Working Group first said "Yes", but then, in response to comments during the first Last Call and based on implementation reports, finally decided "No". This decision was made after weeks of discussion, including discussion at a face-to-face meeting. It was agreed that no consensus solution was possible, so finally a vote was taken, with 12 organizations supporting disjointness, no abstentions, and with Alan opposed.
More details about this issue and its resolution process can be found here:
9.2 Jeremy Carroll
The second objection came from Jeremy Carroll, who participated in the Working Group representing Hewlett-Packard until he left for TopQuadrant. During both the first and second Last Call periods, he submitted multiple lengthy comments on behalf of TopQuadrant. Some of his comments were positive and some were addressed to his satisfaction by the working group. On a few matters he said he was not pleased but would not object, and on one matter he stated he would object.
The issue on which he objects concerns the motivation for and/or branding of OWL 2. He states that many features of OWL 2 are "under-motivated", and either they should be dropped, or "most, if not all, of the new features of OWL2" should be rebranded as "Web-SROIQ". (In the Description Logic research community, "SROIQ" identifies the logic formalism that OWL 2 DL uses.) The Working Group discussed the matter in response to his comments during each Last Call period, but found no serious merit to his arguments on this issue.
For more details see:
11 Patent Disclosures