DCMI Usage Board, DC-2009, Seoul, Korea
Pete Johnston, Eduserv
[email protected]
http://www.eduserv.org.uk/research/
16 October
2009
Relationship between foaf:maker &
dc:creator/dcterms:creator
Background: UsingDublinCoreCreator
• (Content from July 2003 onwards….)
• Discusses historical ambiguity in (ab)use of dc:creator
• Value as
–
–
–
–
Name (literal)
Agent
List of names (literals)
List of Agents
• FOAF community resolution:
– Coined foaf:maker (range = foaf:Agent)
– Recommended using dc:creator (only) with literal value
– Rule for inferring dc:creator triple from
foaf:maker/foaf:name triples
http://wiki.foaf-project.org/w/UsingDublinCoreCreator
DCMI Usage Board, DC-2009, Seoul, Korea
16 October 2009
2
FOAF: foaf:maker
• Property foaf:maker
• http://xmlns.com/foaf/0.1/maker
• “An agent that made this thing.”
• Domain: owl:Thing
• Range: foaf:Agent
DCMI Usage Board, DC-2009, Seoul, Korea
16 October 2009
3
Guidelines
• The foaf:maker property relates something to a foaf:Agent
that foaf:made it. As such it is an inverse of the foaf:made
property.
• The foaf:name (or other rdfs:label) of the foaf:maker of
something can be described as the dc:creator of that thing.
• For example, if the thing named by the URI
http://rdfweb.org/people/danbri/ has a foaf:maker that is a
foaf:Person whose foaf:name is 'Dan Brickley', we can
conclude that http://rdfweb.org/people/danbri/ has a
dc:creator of 'Dan Brickley'.
• FOAF descriptions are encouraged to use dc:creator only for
simple textual names, and to use foaf:maker to indicate
creators, rather than risk confusing creators with their
names. This follows most Dublin Core usage. See
UsingDublinCoreCreator for details.
http://xmlns.com/foaf/spec/#term_maker
DCMI Usage Board, DC-2009, Seoul, Korea
16 October 2009
4
DCMI: dcterms:creator
• January 2008: DCMI coins new property
dcterms:creator
– Range: dcterms:Agent
• October 2009(?): DCMI deletes part of
“comment” for dcterms:creator saying
– “Typically, the name of a Creator should be used to
indicate the entity.”
• Essentially, foaf:maker = dcterms:creator
– But currently not stated formally
DCMI Usage Board, DC-2009, Seoul, Korea
16 October 2009
5
Suggestion (1)
• “Dan wants FOAF to say that foaf:maker is a
sub-property of dcterms:creator and asks
whether DCMI could make a reciprocal claim.”
– https://www.jiscmail.ac.uk/cgibin/webadmin?A2=ind0906&L=DCUSAGE&P=14469
• i.e.
– FOAF says
• foaf:maker rdfs:subPropertyOf dcterms:creator .
– DCMI says
• dcterms:creator rdfs:subPropertyOf foaf:maker .
DCMI Usage Board, DC-2009, Seoul, Korea
16 October 2009
6
Suggestion (1): Discussion
• foaf:maker rdfs:subPropertyOf dcterms:creator .
• Means that
– Thing:A foaf:maker Agent:P .
=> Thing:A dcterms:creator Agent:P .
– And (from rdfs:range)
• Agent:P a dcterms:Agent .
– And (from rdfs:subPropertyOf)
• Thing:A dcterms:contributor Agent:P .
• Thing:A dc:contributor Agent:P .
• Thing:A dc:creator Agent:P .
DCMI Usage Board, DC-2009, Seoul, Korea
16 October 2009
7
Suggestion (1): Discussion
• dcterms:creator rdfs:subPropertyOf foaf:maker .
• Means that
– Thing:B dcterms:creator Agent:Q .
=> Thing:B foaf:maker Agent:Q .
– And (from rdfs:range)
• Agent:Q a foaf:Agent .
– And (from rdfs:domain)
• Thing:B a owl:Thing .
– And (from owl:inverseOf)
• Agent:Q foaf:made Thing:B .
DCMI Usage Board, DC-2009, Seoul, Korea
16 October 2009
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Suggestion (2)
• FOAF changes the guideline for foaf:maker to
remove the text encouraging the use of
dc:creator with literal values?
• N.B. following suggestion (1)
– Thing:A foaf:maker Agent:P .
– => Thing:A dc:creator Agent:P .
DCMI Usage Board, DC-2009, Seoul, Korea
16 October 2009
9
Issues
• Semantic
– Generally, mutual subproperty assertions not a problem
in RDFS
– For these two properties, mutual subproperty assertions
generate no unwanted entailments (AFAICT!)
– Not necessary for FOAF & DCMI to publish assertions at
exactly the same time
• “Social”
– “Setting a precedent”?
– Will we be asked to make other such assertions?
– What are criteria for deciding to consider such requests?
• Are there other assertions we might make re terms in
other vocabularies? e.g. (examples only!)
– dcterms:type rdfs:subPropertyOf rdf:type .
– dcterms:title rdfs:subPropertyOf rdfs:label .
DCMI Usage Board, DC-2009, Seoul, Korea
16 October 2009
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Proposal (provisional pending discussion)
• For the property dcterms:creator
– add the assertion that
• dcterms:creator rdfs:subPropertyOf foaf:maker .
DCMI Usage Board, DC-2009, Seoul, Korea
16 October 2009
11
Relationship between foaf:maker &
dc:creator/dcterms:creator
Title slide photo “Korean Folk Drumming” by Flickr user paul walk
See http://www.flickr.com/photos/paulwalk/4011459348//
Made available under CC Attribution 2.0 license
DCMI Usage Board, DC-2009, Seoul, Korea
16 October 2009
12
DCMI Usage Board, DC-2009, Seoul, Korea
Pete Johnston, Eduserv
[email protected]
http://www.eduserv.org.uk/research/
16 October
2009
Relationship between foaf:maker &
dc:creator/dcterms:creator