- From: Andy Seaborne <andy.seaborne@epimorphics.com>
- Date: Tue, 10 Apr 2012 14:31:10 +0100
- To: public-rdf-wg@w3.org
On 10/04/12 14:14, Ivan Herman wrote: > Just my immediate reaction on this... > > What this use case seem to demand is some possibilities to manipulate graphs explicitly, that is to create the union (in the RDF) sense of graphs (that is the way I interpret this 'Frame' concept). > > The question is whether this is left in the application domain, via some sort of API on the RDF environment (the RDF environment I know the most, namely RDFLib, has operations to create the union of graphs) or whether we need some declarative/syntax means for that. Something like (using Tom's pseudo-code): > > <u> { P has_title "Moby-Dick, or, the Whale"; P has_as_subject "Whaling Ships -- Fiction" } > <v> { Q has_language "English" ; Q has_extent "213711 words" } > { > <f> rdf:unionOf (<u> <v> ) . > } > > or, alternatively, some syntax that explicitly says that the Default Graph includes the union of all those graphs, but I am not sure what syntax one would use for that... > > Ivan As well as union, there is something else going on. -- Named Graph D, a Work-level description P has_title "Moby-Dick, or, the Whale" -- Named Graph A, an Item-level description X has_OAI_ID http://hdl.handle.net/10150/16470 ==> X has_title "Moby-Dick, or, the Whale" so some inference happened: P a :work P has_title "..." X a :Item FrameL includes NamedGraphA FrameL includes NamedGraphD ==> X has_title "..." Andy > > > > On Apr 10, 2012, at 15:05 , Ivan Herman wrote: > >> I am not sure all of you read the RDF Comment mailing list, so, to be on the safe side, I forward this mail... >> >> Ivan >> >> Begin forwarded message: >> >>> Resent-From: public-rdf-comments@w3.org >>> From: Thomas Baker<tom@tombaker.org> >>> Subject: Use Case: "Expressing FRBR Descriptions using Named Graphs" >>> Date: April 4, 2012 23:44:38 GMT+02:00 >>> To: public-rdf-comments@w3.org >>> Cc: Ron Murray<kandroma1@me.com>, Barbara Tillett<btil@loc.gov>, Gordon Dunsire<gordon@gordondunsire.com> >>> Archived-At:<http://www.w3.org/mid/20120404214438.GA47236@julius> >>> List-Id:<public-rdf-comments.w3.org> >>> >>> Dear Members of the RDF Working Group, >>> >>> The following text describes a proposed use case for Named Graphs. For anyone >>> unfamiliar with "FRBR," the Wikipedia page provides a quick overview [1]. FRBR >>> is the foundation for RDA (Resource Description and Access), the new cataloging >>> standard towards which major libraries are moving [2]. >>> >>> This proposal for conceptualizing FRBR entities as Named Graphs is based on >>> work by Ronald Murray and Barbara Tillett of the Library of Congress. These >>> ideas are illustrated in a visually very engaging slide deck, "From Moby-Dick >>> to Mash-Ups: Thinking About Bibliographic Networks" [3]. Gordon Dunsire has >>> also contributed to the proposal. >>> >>> We would be especially grateful for feedback in advance of an event on 27 April >>> at the British Library [4]. The event will mark the fifth anniversary of a >>> meeting in May 2007 which resulted in a recommendation that RDA and FRBR be >>> expressed in RDF [5]. >>> >>> The Named Graph approach outlined below is a relatively new contribution to >>> this ongoing thread. As the approach depends on the resolution of issues still >>> under discussion in the RDF Working Group, we would much appreciate your >>> comments or suggestions. >>> >>> Tom >>> >>> [1] http://en.wikipedia.org/wiki/Functional_Requirements_for_Bibliographic_Records >>> [2] http://en.wikipedia.org/wiki/Resource_Description_and_Access >>> [3] http://www.slideshare.net/RonMurray/from-mobydick-to-mashups >>> [4] http://dcevents.dublincore.org/index.php/BibData/fyo >>> [5] http://www.bl.uk/bibliographic/meeting.html >>> >>> ---------------------------------------------------------------------- >>> Expressing FRBR Descriptions using Named Graphs: a proposal >>> >>> W3C's Resource Description Framework (RDF) Working Group [1] is currently >>> discussing proposals for supporting "named graphs" to meet a wide range of use >>> cases [2], possibly by extending the TriG Named Graph and RDF Data Language >>> [3,4]. This proposal outlines how Named Graphs might be used in resource >>> descriptions that are based on the so-called WEMI entities (Work, Expression, >>> Manifestation, and Item) of the IFLA model Functional Requirements for >>> Bibliographic Records (FRBR) [5]. >>> >>> This proposal views descriptions of WEMI entities as bundles of statements made >>> at different levels of abstraction, from the most concrete Item level to the >>> most abstract Work level. Multi-level WEMI descriptions specify the >>> characteristics that any given Item shares with other Items at the level of >>> Work, Expression, and Manifestation. Ideally, it would be possible to >>> incorporate descriptions of resources at the Work, Expression, and >>> Manifestation levels, maintained in a distributed manner by various >>> institutions, into the local descriptions of particular Items. >>> >>> Consider the following four Named Graphs, each of which is identified with a >>> URI (A, B, C, or D) and contains two statements: >>> >>> -- Named Graph D, a Work-level description >>> P has_title "Moby-Dick, or, the Whale" >>> P has_as_subject "Whaling Ships -- Fiction" >>> >>> -- Named Graph C, an Expression-level description >>> Q has_language "English" >>> Q has_extent "213711 words" >>> >>> -- Named Graph B, a Manifestation-level description >>> R has_edition_issue "First Edition" >>> R has_pub_place "New York NY" >>> >>> -- Named Graph A, an Item-level description >>> X has_OAI_ID http://hdl.handle.net/10150/16470 >>> X has_condition "yellowing at page edges" >>> >>> One might bind these four chunks into a single description by "including" them >>> into a common "frame": >>> >>> FrameL includes NamedGraphA >>> FrameL includes NamedGraphB >>> FrameL includes NamedGraphC >>> FrameL includes NamedGraphD >>> >>> One would then want to infer that the Item in hand (described by the statements >>> in Named Graph A) is _also_ described by statements in the Named Graphs at the >>> more abstract levels of Work, Expression, and Manifestation included in the >>> same Frame. In other words, if X is the URI of the Item in hand, one would >>> like to infer: >>> >>> X has_title "Moby-Dick, or, the Whale" >>> X has_as_subject "Whaling Ships -- Fiction" >>> X has_language "English" >>> X has_extent "213711 words" >>> X has_edition_issue "First Edition" >>> X has_pub_place "New York NY >>> X has_OAI_ID http://hdl.handle.net/10150/16470 >>> X has_condition "yellowing at page edges" >>> >>> Discussion >>> >>> 1. Formal notions of Frame, and of "inclusion" in a Frame, would need to be >>> defined for the general case. >>> >>> 2. Formal rules would be needed for interpreting Frames with different >>> sets of FRBR descriptions, e.g., for the simple case above, in which >>> statements from Work-, Expression-, and Manifestation-level descriptions are >>> interpreted as applying to the Item. >>> >>> 3. Given the complex, even chaotic nature of the Web, flexibility to >>> implement this approach in a partial manner is a critical design criterion. >>> Particular WEMI descriptions should be useful in a Linked Data environment >>> independently of particular Frames and, ideally, even in the absence of an >>> understanding of Frames and Inclusion (see 1 above) or of the particular >>> rules applicable to FRBR (see 2 above). In the example described above, the >>> statements in Named Graph D about Work P would be useful independently of >>> FrameL, which (according to rules yet to be defined) would merely apply >>> those statements, additionally, to Item X. >>> >>> References >>> >>> [1] http://www.w3.org/2011/rdf-wg/ >>> [2] http://www.w3.org/2011/rdf-wg/wiki/Why_Graphs >>> [3] http://dvcs.w3.org/hg/rdf/raw-file/default/trig/index.html# >>> [4] http://lists.w3.org/Archives/Public/public-rdf-wg/2012Mar/0123.html >>> [5] http://www.ifla.org/VII/s13/frbr/frbr.htm >>> >>> -- >>> Tom Baker<tom@tombaker.org> >>> >>> >> >> >> ---- >> Ivan Herman, W3C Semantic Web Activity Lead >> Home: http://www.w3.org/People/Ivan/ >> mobile: +31-641044153 >> FOAF: http://www.ivan-herman.net/foaf.rdf >> >> >> >> >> > > > ---- > Ivan Herman, W3C Semantic Web Activity Lead > Home: http://www.w3.org/People/Ivan/ > mobile: +31-641044153 > FOAF: http://www.ivan-herman.net/foaf.rdf > > > > >
Received on Tuesday, 10 April 2012 13:31:50 UTC