This is an example of one of the mapping patterns identified for MARC21 00X attributes. In this case, up to four codes for illustrations can be used for specific categories of resource, and there is no significance in the order of the codes.This is an RDF graph of the mapping. The four Level 0 properties corresponding to the attributes are mapped as sub-properties of a generic attribute for the category of material, which in turn is mapped as a sub-property of a generic attribute for all categories of material.
This is another example of a mapping pattern for MARC21 00x attributes where up to four codes can be used for information about the relief of a cartographic resource. The order of the codes and the attributes used is significant, with the most prominent form of relief recorded in the first attribute, and the fourth most prominent, if any, recorded in the last attribute.This is a partial RDF graph of the mapping, showing only the first Level 0 attribute in each category of resource. Each is mapped as a sub-property of a generic attribute for the category of material and also as a sub-property of a generic attribute for the first, most prominent attribute. Each generic attribute in turn is mapped as a sub-property of a generic attribute for all categories of material.The graph omits the mappings from the second, third, and fourth Level 0 attributes.
This is an example of using the Level 0 properties for MARC21 00X attributes for a real record.The record contains only a 008 field, and this is a complete RDF graph of corresponding triples.Note the graph omits the Type of record attribute from the Leader field, which corresponds to Form of material attribute from field 006. This treatment of the Leader field is still under investigation.The graph uses controlled vocabularies from the Library of Congress Authorities at id.loc.gov as well as those specific to the 00X attributes available from the Open Metadata Registry.Note the inclusion of the data for Conference publication, Festschrift, and Index. Many mappings would simply exclude these when they have a non-positive value. But the Semantic Web has an “Open World Assumption” that the absence of a particular statement just means, in principle, that the statement has not been made explicitly yet. Publishing the explicit statements that, in this case, the resource is not a conference publication or festschrift, and has no index, avoids a user of the data having to make the assumption.
This is another example of using the Level 0 properties for MARC21 00X attributes for a real record.The record contains one 006, two 007 and one 008 fields, and this is a partial RDF graph of corresponding triples.Note the inclusion of the “not applicable” data for Form of composition of Music. Again, it is useful to publish this triple to avoid invoking the Open World Assumption.
MFIG on MARC21rdf
MARC21 as RDFNow that it‟s there, what can we do with it?
Questions for Today Why did we decide to do this? How did we do it? What is this, really? What does this look like? Where do we go from here? ALA Dallas 1/20/12
Why Did We Do This? We‟re very interested in the problems of mapping in the Semantic Web ◦ See paper: http://dcevents.dublincore.org/index.php/I ntConf/dc-2011/paper/view/52 We wanted to explore these issues in the context of MARC21 Others doing maps had cherry-picked available properties—we wanted to do them all ALA Dallas 1/20/12
How Did We Do It? OMR has lacked upload capability— that was built for this purpose by Jon Phipps, OMR developer Gordon Dunsire built all the spreadsheets in Google Docs, including the URI patterns I did most of the testing and some of the error handling Not rocket science, but a solid few weeks of work ALA Dallas 1/20/12
What Is It Good For? It‟s the beginning, not the ending … There‟s more work to be done, but we wanted people to be able to use it for experimentation right away We included *almost* everything— over 10,600 properties and vocabulary concepts in all It can be downloaded in pieces, we haven‟t yet set up an „everything‟ download capability (we will) ALA Dallas 1/20/12
MARC21 in the Open MetadataRegistry Separate RDF property available ◦ For every attribute in the fixed-data fields Based on character position ◦ For every combination of indicators and subfield codes within a tag Including non-filing indicators Some tags excluded (for now) RDF/SKOS vocabularies (with definitions!) available for all code lists for the fixed-data fields ALA Dallas 1/20/12
MARC21 in the Open MetadataRegistry There‟s a consistent pattern used to coin marc21rdf.info URIs Designed to enable a knowledgeable cataloger to „guess‟ the correct URI… ALA Dallas 1/20/12
MARC21 in the Open MetadataRegistry URIs for properties based on the MARC21 encoding ◦ “M” + tag + indicator 1 + indicator 2 + subfield code Underscore substituted for blank E.g. M24011d ◦ Date of treaty signing in Uniform Title, with 1 nonfiling character and intended to be printed or displayed ALA Dallas 1/20/12
MARC21 in the Open MetadataRegistry URIs for concepts based on the MARC21 codes ◦ E.g. a (code for playback speed of a sound recording) ◦ 16 rpm Each vocabulary and concept has its own URI ◦ E.g. soundrecordingspd# ◦ E.g. soundrecordingspd#a (for 16 rpm) ALA Dallas 1/20/12
MARC21 in the Open MetadataRegistry Data from MARC21 legacy records can be mechanically-mapped to the corresponding RDF properties at “Level 0” Level 0 properties can be mapped to a series of more generic properties (Level 1 and above) ◦ To clarify and separate semantics from syntax ◦ Relatively simple for fixed-data fields, but significant issues to be tackled for variable tags. ALA Dallas 1/20/12
MARC21 in the Open MetadataRegistry Generic properties can be used to map from MARC21 to other metadata schemas/formats ◦ Example goal: from MARC21 title (245 $a) to Dublin Core title, ISBD title proper, RDA manifestation title, etc. MARC21 data can be retained in RDF without loss of semantics or values, and made interoperable with data from other sources via semantic relationships ALA Dallas 1/20/12
RDF graph of 00X mapping pattern for an attribute with more than one valueand no significance in the order of values ALA Dallas 1/20/12
Partial RDF graph of 00X mapping pattern for two or more attributes withmore than one value and significance in the order of values ALA Dallas 1/20/12
RDF graph of 00X data from National Library of Scotland record forLegacy by Robert Buchanan ALA Dallas 1/20/12
Partial RDF graph of 00X data from OCLC record for Abbey Road by the Beat ALA Dallas 1/20/12
Property Detail: Relator codes ALA Dallas 1/20/12
What‟s Left To Do? Build on the „Level 0‟ representations to better reflect the reality and complexity of MARC21 Continue to explore the usefulness of the process we used, and how it might be used for other element sets Write it up for the benefit of others New DCMI Vocabulary Management Community seems a good place for this activity ALA Dallas 1/20/12
Questions? Contact for Diane: email@example.com Contact for Gordon firstname.lastname@example.org ◦ (the middle section of slides were his) Please let us know what you think! ALA Dallas 1/20/12