In the specific case of RDF, having your cake and eating it doesn't work.  Paste this:

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
                 xmlns:dwc="http://rs.tdwg.org/dwc/terms/"
                 >
<dwc:Occurrence rdf:about="http://herbarium.org/hb123456">                
<dwc:recordedBy rdf:resource="http://people.vanderbilt.edu/~steve.baskauf/foaf.rdf#me">Steve Baskauf</dwc:recordedBy>
</dwc:Occurrence>
</rdf:RDF>

into the W3C RDF validator at:
http://www.w3.org/RDF/Validator/
and it will tell you "The attributes on this property element, are not permitted with any content; expecting end element tag.".  So in RDF elements having the rdf:resource attribute have to be empty elements.  I tried validating an example where the recordedBy property was included twice, once with a URI object and once with a string literal object.  It validated as "good" RDF, but I think it would be confusing to a linked data client that would really have no clue that both objects represented the same thing and would probably "assume" that the occurrence was recorded by two entities rather than one.. 

A possible solution would be to use dcterms:description as another attribute.  dcterms:description is defined as "An account of the resource.  Description may include ...a free-text account of the resource."  I couldn't find a more appropriate Dublin Core to use as an attribute.  So running this example:

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
                xmlns:dcterms="http://purl.org/dc/terms/"
                 xmlns:dwc="http://rs.tdwg.org/dwc/terms/"
                 >
<dwc:Occurrence rdf:about="http://herbarium.org/hb123456">                
<dwc:recordedBy rdf:resource="http://people.vanderbilt.edu/~steve.baskauf/foaf.rdf#me" dcterms:description="Steve Baskauf" />
</dwc:Occurrence>
</rdf:RDF>

through the validator shows that this RDF asserts the following triples:
http://herbarium.org/hb123456  dwc:recordedBy      http://people.vanderbilt.edu/~steve.baskauf/foaf.rdf#me
and that
http://people.vanderbilt.edu/~steve.baskauf/foaf.rdf#me  dcterms:description  "Steve Baskauf"

In other words, the occurrence was recorded by me (identified by my URI) and that the description of the thing represented by my URI is "Steve Baskauf".  That is pretty much a correct representation of the situation, although the whole point of using a URI as the object of a property is for a client to dereference the URI to find out more about the object.  The FOAF file (pointed to by the URI) would provide that information without the dcterms:description attribute.

Steve


Jim Croft wrote:
wondering if
<dwc:recordedBy
rdf:resource="http://people.vanderbilt.edu/~steve.baskauf/foaf.rdf#me">Steve
Baskauf</dwc:recordedBy>
is legit?

just a have your cake and eat it kinda guy...

jim

On Thu, May 20, 2010 at 7:41 AM, Kevin Richards
<RichardsK@landcareresearch.co.nz> wrote:
  
From my understanding (and after reading the example Bob referred to), the difference is:

[referring to external id]
<dwc:recordedBy rdf:resource="http://people.vanderbilt.edu/~steve.baskauf/foaf.rdf#me" />

[inline text]
<dwc:recordedBy>Steve Baskauf</dwc:recordedBy>

Look right?

Kevin

-----Original Message-----
From: tdwg-tag-bounces@lists.tdwg.org [mailto:tdwg-tag-bounces@lists.tdwg.org] On Behalf Of Jim Croft
Sent: Thursday, 20 May 2010 9:37 a.m.
To: Bob Morris
Cc: tdwg-tag@lists.tdwg.org
Subject: Re: [tdwg-tag] string literals vs. uris for dwc:recordedBy, dwc:identifiedBy, and dwc:georeferencedBy in RDF

Hi Bob - should the same term allow both types of content, or should
there be a different term for each?  Does it matter?  Should
applications be smart enough to tell the difference and know what to
do with it?

Not really asking what the specification says, but about purity and
wholesomeness of design... :)

jim

On Thu, May 20, 2010 at 4:26 AM, Bob Morris <morris.bob@gmail.com> wrote:
    
Exactly this example is given in
http://web4.w3.org/TR/REC-rdf-syntax/#section-Syntax-property-attributes
so I would find it regrettable if DwC does something somewhere that
makes this substitution impossible or discouraged,  or encourages tool
construction that does so, or encourages documention be interpreted in
a way that does so.

Indeed http://rs.tdwg.org/dwc/rdf/dwcterms.rdf defines its type to be
rdf:Property and is silent on any semantics  but that. My own
conclusion is that neither the intent or the outcome of the rdf
version of dwcterms discourages what you want, though I suppose the
intent part would be clearer if the documentation also said that a URI
can always be used, but applications are responsible for interpreting
it.


On Wed, May 19, 2010 at 11:09 AM, Steve Baskauf
<steve.baskauf@vanderbilt.edu> wrote:
      
The definition for the Darwin Core term recordedBy
http://rs.tdwg.org/dwc/terms/index.htm#recordedBy
says "A list (concatenated and separated) of names ...".  The examples
given are string literals.  However, when using this term as a predicate
in RDF, it would seem preferable to use a URI to an RDF representation
of the entity (if one exists) rather than a string literal.  For
example, can I use:
<dwc:recordedBy
rdf:resource="http://people.vanderbilt.edu/~steve.baskauf/foaf.rdf#me"/>
rather than
<dwc:recordedBy>Steven J. Baskauf</dwc:recordedBy>
?

Steve Baskauf
--

Steven J. Baskauf, Ph.D., Senior Lecturer
Vanderbilt University Dept. of Biological Sciences

postal mail address:
VU Station B 351634
Nashville, TN  37235-1634,  U.S.A.

delivery address:
2125 Stevenson Center
1161 21st Ave., S.
Nashville, TN 37235

office: 2128 Stevenson Center
phone: (615) 343-4582,  fax: (615) 343-6707
http://bioimages.vanderbilt.edu

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--
Robert A. Morris
Emeritus Professor  of Computer Science
UMASS-Boston
100 Morrissey Blvd
Boston, MA 02125-3390
Associate, Harvard University Herbaria
email: ram@cs.umb.edu
web: http://bdei.cs.umb.edu/
web: http://etaxonomy.org/FilteredPush
http://www.cs.umb.edu/~ram
phone (+1)617 287 6466
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--
_________________
Jim Croft ~ jim.croft@gmail.com ~ +61-2-62509499 ~
http://www.google.com/profiles/jim.croft
'A civilized society is one which tolerates eccentricity to the point
of doubtful sanity.'
 - Robert Frost, poet (1874-1963)
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-- 
Steven J. Baskauf, Ph.D., Senior Lecturer
Vanderbilt University Dept. of Biological Sciences

postal mail address:
VU Station B 351634
Nashville, TN  37235-1634,  U.S.A.

delivery address:
2125 Stevenson Center
1161 21st Ave., S.
Nashville, TN 37235

office: 2128 Stevenson Center
phone: (615) 343-4582,  fax: (615) 343-6707
http://bioimages.vanderbilt.edu