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Short presentation to DCMI Social Tagging Community session at DC-2007, Singapore, 2007-08-30.
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30
Au
gu
st 20
07
Pete Johnston, Eduserv [email protected]
www.eduserv.org.uk/foundation
dctagging: Encoding DC metadata using Structured Tags
DCMI Social Tagging CommunityDC-2007: Application Profiles: Theory and Practice, Singapore
30 August 2007DC-2007: Application Profiles: Theory and Practice, Singapore
2
dctagging: DC metadata using Structured Tags
• Context and motivation
• Structured tagging– geotagging
– dctagging
• dctagging and DCAM
• Flickr machine tags
30 August 2007DC-2007: Application Profiles: Theory and Practice, Singapore
3
Context & Motivation
30 August 2007DC-2007: Application Profiles: Theory and Practice, Singapore
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Context and motivation
• Tagging indicates some undefined relationship between the subject resource and the tag
• Tag may be indicator of– topic/”about-ness” e.g. “SecondLife”, “openAccess”
– genre/”type” e.g. “tutorial”
– status e.g. “toRead”, “possibleBlogPost”
– provenance/publisher e.g. “DCMI”, “JISC”
– creator e.g. “Berners-LeeTim”, “BakerMark”
• How do I distinguish resources about TBL from resources created by TBL?
30 August 2007DC-2007: Application Profiles: Theory and Practice, Singapore
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Structured Tagging
30 August 2007DC-2007: Application Profiles: Theory and Practice, Singapore
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Structured Tagging
• Use of tag as “multi-part” entity– e.g. tag as key-value pair
• “Triple tagging”– three parts: prefix, key, value– interpretation as triple: subject URI, predicate/property
URI, literal
• Geotagging– geo:lat=51.4989 – geo:lon=-0.1786– geotagged– Widely used in Flickr for photograph locations– See http://geobloggers.com/
30 August 2007DC-2007: Application Profiles: Theory and Practice, Singapore
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Structured Tagging
• dctagging– DC metadata as prefixed key-value pairs in tags
– dc:creator=Berners-LeeTim
– dc:publisher=UKOLN
– dctagged
• See – http://efoundations.typepad.com/efoundations/2006/
10/dctagged.html
30 August 2007DC-2007: Application Profiles: Theory and Practice, Singapore
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dctagging & DCAM
30 August 2007DC-2007: Application Profiles: Theory and Practice, Singapore
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dctagging and the DCMI Abstract Model
• Need to decide on DCAM interpretation
• Triple tag = prefixed/key/value
• “dctagged” as implicit “namespace declaration”
• Note: no way to distinguish between
– literal value surrogate and non-literal value surrogate
• Propose
– Tag -> DCAM Statement
– Prefix/key -> DCAM Property URI
– Value -> DCAM Literal Value Surrogate Value String
• i.e. literal values only
30 August 2007DC-2007: Application Profiles: Theory and Practice, Singapore
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Flickr machine tags
30 August 2007DC-2007: Application Profiles: Theory and Practice, Singapore
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Flickr machine tagging
• del.icio.us has no built-in support for triple tagging
• Can’t do e.g.– "find all items for which the value of the dc:creator property is a
literal that begins with 'Powell'" or – "find all items related (by any property) to the literal 'PowellAndy'“
• Flickr support for “machine tags” – Uses namespacing convention borrowed from XML Namespaces– xmlns:dc=http://purl.org/dc/elements/1.1/– Flickr API supports queries using structured tags
– http://www.flickr.com/groups/api/discuss/72157594497877875/
• See also Dave Beckett’s Flickcurl– http://librdf.org/flickcurl/
30 August 2007DC-2007: Application Profiles: Theory and Practice, Singapore
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Expressing the Scholarly Works (Eprints) DC Application Profile using the DSP wiki syntax
Title slide photo of Singapore Orchid Gardens by Flickr user Andries3See http://www.flickr.com/photos/andriesoudshoorn/458678695/Made available under CC Attribution-NonCommercial 2.0 license
30
Au
gu
st 20
07
Pete Johnston, Eduserv [email protected]
www.eduserv.org.uk/foundation
Expressing the Scholarly Works (Eprints) DC Application Profile using the DSP wiki syntax
DC-2007: Application Profiles: Theory and Practice, Singapore
