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16
Octo
ber 2
00
9
Pete Johnston, [email protected]
http://www.eduserv.org.uk/research/
Relationship between foaf:maker & dc:creator/dcterms:creator
DCMI Usage Board, DC-2009, Seoul, Korea
16 October 2009DCMI Usage Board, DC-2009, Seoul, Korea 2
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
16 October 2009DCMI Usage Board, DC-2009, Seoul, Korea 3
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
16 October 2009DCMI Usage Board, DC-2009, Seoul, Korea 4
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
16 October 2009DCMI Usage Board, DC-2009, Seoul, Korea 5
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
16 October 2009DCMI Usage Board, DC-2009, Seoul, Korea 6
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/cgi-bin/webadmin?A2=ind0906&L=DC-USAGE&P=14469
• i.e. – FOAF says
• foaf:maker rdfs:subPropertyOf dcterms:creator .
– DCMI says• dcterms:creator rdfs:subPropertyOf foaf:maker .
16 October 2009DCMI Usage Board, DC-2009, Seoul, Korea 7
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 .
16 October 2009DCMI Usage Board, DC-2009, Seoul, Korea 8
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 .
16 October 2009DCMI Usage Board, DC-2009, Seoul, Korea 9
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 .
16 October 2009DCMI Usage Board, DC-2009, Seoul, Korea 10
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 .
16 October 2009DCMI Usage Board, DC-2009, Seoul, Korea 11
Proposal (provisional pending discussion)
• For the property dcterms:creator– add the assertion that
• dcterms:creator rdfs:subPropertyOf foaf:maker .
16 October 2009DCMI Usage Board, DC-2009, Seoul, Korea 12
Relationship between foaf:maker & dc:creator/dcterms:creator
Title slide photo “Korean Folk Drumming” by Flickr user paul walkSee http://www.flickr.com/photos/paulwalk/4011459348//Made available under CC Attribution 2.0 license
16
Octo
ber 2
00
9
Pete Johnston, [email protected]
http://www.eduserv.org.uk/research/
Relationship between foaf:maker & dc:creator/dcterms:creator
DCMI Usage Board, DC-2009, Seoul, Korea
