W3C home > Mailing lists > Public > public-lod@w3.org > January 2011

Re: Is it best practices to use a rdfs:seeAlso link to a potentially multimegabyte PDF?, existing predicate for linking to PDF?

From: Niklas Lindström <lindstream@gmail.com>
Date: Sat, 8 Jan 2011 15:07:37 +0100
Message-ID: <AANLkTimdVx6+keRP_tjD19bweDzq-6p17TVcrJTuMF0C@mail.gmail.com>
To: Peter DeVries <pete.devries@gmail.com>
Cc: public-lod@w3.org
Hi Peter!

I suggest using DC terms for as much as possible for these kinds of
things (information resource descriptions with related
representations).

So instead of txn:hasPDFVersion, this may be more generally understood:

  <http://lod.taxonconcept.org/ses/v6n7p#OriginalDescription>
    dct:hasFormat
<http://assets.geospecies.org/spec_concept_uuid/603bebac-cc44-4168-bbf7-b11b976f9d79/Felis_concolor_Linnaeus_1771.pdf>
.

  <http://assets.geospecies.org/spec_concept_uuid/603bebac-cc44-4168-bbf7-b11b976f9d79/Felis_concolor_Linnaeus_1771.pdf>
    dct:format "application/pdf" .

Specifying the file size could also be beneficial (given your
potential use cases). I'm not sure about any better property than
dct:extent, although it's vague on the range (so the value should be
datatyped as "bytes" or similar). I'd also suggest looking at either
AtomOwl's awol:length or dcat's dcat:size/dcat:bytes as well.

.. Note the semantical similarity to how one in Atom would write something like:

  <link rel="alternate"
href="http://assets.geospecies.org/spec_concept_uuid/603bebac-cc44-4168-bbf7-b11b976f9d79/Felis_concolor_Linnaeus_1771.pdf"
type="application/pdf" length="1234567"/>


Also, I'd use dct:creator instead of txn:hasAuthorURI, and dct:created
with an xsd:gYear-literal instead of txn:year:

  <http://lod.taxonconcept.org/ses/v6n7p#OriginalDescription>
    dct:creator <http://dbpedia.org/resource/Carl_Linnaeus>;
    dct:created "1771"^^xsd:gYear .


All of this could (at least to some extent) also be inferred given
appropriate ontology statements (such as owl:equivalentProperty or
some N3 formulae for the PDF bits) about the txn properties. But
unless a high level of terseness is achieved, I think using the DC
terms directly gives more uniform data (easier to integrate and so
on).

(Finally, your example has "wdrs:describedBy", which I don't think
exists. AFAIK, it should be the all lowercased "wdrs:describedby".)

Best regards,
Niklas Lindström



On Thu, Jan 6, 2011 at 8:40 PM, Peter DeVries <pete.devries@gmail.com> wrote:
> I was wondering if there is an existing predicate for linking to a PDF file?
> I would like to incorporate a link between bibliographic reference
> description and a URL to the location of a PDF of that document.
>
> I had minted a predicate txn:hasPDFVersion, as demonstrated in this RDF
> snippet. (Part of http://lod.taxonconcept.org/ses/v6n7p.rdf )
>   <txn:SpeciesOriginalDescription
> rdf:about="http://lod.taxonconcept.org/ses/v6n7p#OriginalDescription">
>     <!-- Ideally, this should link to a resource in the Biodiversity
> Heritage Library -->
>     <dcterms:title>Original Published Description relating to Species
> Concept Puma concolor se:v6n7p</dcterms:title>
>
>  <dcterms:identifier>http://lod.taxonconcept.org/ses/v6n7p#OriginalDescription</dcterms:identifier>
>     <dcterms:description>LOD metadata about the original species description
> relating to Species Concept Puma concolor se:v6n7p</dcterms:description>
>     <dcterms:isPartOf
> rdf:resource="http://lod.taxonconcept.org/ses/v6n7p#Species"/>
>     <txn:hasAuthorURI
> rdf:resource="http://dbpedia.org/resource/Carl_Linnaeus"/>
>     <txn:hasBasionymName>Felis concolor Linnaeus 1771</txn:hasBasionymName>
>     <txn:year>1771</txn:year>
>     <txn:hasPDFVersion
> rdf:resource="http://assets.geospecies.org/spec_concept_uuid/603bebac-cc44-4168-bbf7-b11b976f9d79/Felis_concolor_Linnaeus_1771.pdf"/>
>     <txn:speciesOriginalDescriptionHasSpeciesConcept
> rdf:resource="http://lod.taxonconcept.org/ses/v6n7p#Species"/>
>     <!-- There should be a type specimen. Add link to GBIF via
> 'txn:sodHasTypeSpecimen' if they know about it. -->
>     <wdrs:describedBy
> rdf:resource="http://lod.taxonconcept.org/ses/v6n7p.rdf"/>
>   </txn:SpeciesOriginalDescription>
> Some have suggested using rdfs:seeAlso to link to what could be a
> multimegabyte PDF, but I think this would cause problems for a number of RDF
> crawlers like Elmo.
> In summary, I think it would be useful to have a predicate that can be used
> for linking specifically to a PDF document.
> Is there an existing predicate for this?
> What do people think about the suggestion to use rdfs:seeAlso to link to a
> PDF?
> I would also like to know of others thoughts or suggestions regarding this
> issue,
> Respectfully,
> - Pete
>
>
> ---------------------------------------------------------------
> Pete DeVries
> Department of Entomology
> University of Wisconsin - Madison
> 445 Russell Laboratories
> 1630 Linden Drive
> Madison, WI 53706
> TaxonConcept Knowledge Base / GeoSpecies Knowledge Base
> About the GeoSpecies Knowledge Base
> ------------------------------------------------------------
>
Received on Saturday, 8 January 2011 14:08:24 UTC

This archive was generated by hypermail 2.3.1 : Sunday, 31 March 2013 14:24:31 UTC