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RDFa ok - adding structured data to MusicBrainz HTML to commence

Last week during the MusicBrainz developer meeting, we presented some experiments about including RDFa in MusicBrainz HTML pages.  The results suggest that the page size (just the HTML file) will increase by between 5% and 30%.

Learning from RDB2RDF at W3C

The LinkedBrainz project is primarily about mapping a relation database (the MusicBrainz DB) into RDF. The W3C RDB2RDF Working Group is focused on use cases just like this. The mission of the working group is to standardize a language for mapping relational data and relational database schemas into RDF and OWL. Richard Cyganiak recommended a video of the working group's recent panel discussion.

From Relational Databases to the Semantic Web: New W3C Standards and Directions Part One from Semantic Universe on Vimeo.

Content and documentation licensing

MusicBrainz has an established and clear set of licensing terms for its database content and the contents of its wiki. Of course, the linked data translation of the MusicBrainz database contents will be offered under the same Public Domain license applied to the MusicBrainz database contents. However, some content in the MusicBrainz database is licensed as by-nc-sa including annotations and folksonomy tags. JISC considers this license incompatible with completely open data. Therefore, this small subset of the MusicBrainz database will likely be omitted from our translation moving forward.

Pagination in RDF

The HTML pages on MusicBrainz use lots of pagination. This not only prevents the end user from being overwhelmed by a listing of thousands of tracks, it reduces the size of HTML pages to something manageable and also ensures a smaller and predictable load on the database server.

In RDF, it would be preferable to avoid pagination. However, this is not particularly practical for artists that are associated with many, many releases and recordings. The problem becomes acute for classical composers like Bach who are credited with tens of thousands recordings. Arguably a more appropriate utilization of NGS would have composers such as Bach credited to works rather than recordings. However, the general opinion of MB editors seems to favor crediting composers as well as performers on recordings. Therefore, the complete RDF resource description for Bach would be immense. This would cause an unacceptable load on the database server and long wait times for dereferenced URIs. One solution is to use pagination in RDF. Terms to support this exist in the XHTML Vocabulary which is generally intended for use with RDFa on paginated websites.

Project Plan Post 7 of 7: Budget

  1. Directly Incurred (Total £47239)
    • a) Staff Postdoctoral RA £41588
    • b) Non-staff
      Travel and expenses £2200
      Hardware/software £1451
      Dissemination £2000
  2. Directly Allocated (Total £24619)
    Staff £11133
    Estates £12550
    Other £936
  3. Indirect Costs (Total £46759)

Total Project Cost = £118617, consisting of:

Funding from JISC: £94894
Institutional contributions: £23723

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