- From: Butler, Mark <Mark_Butler@hplb.hpl.hp.com>
- Date: Mon, 7 Apr 2003 12:10:24 +0100
- To: www-rdf-dspace@w3.org
Eric, MacKenzie, please can I give you an action to agree on the text for section 3.2.4? Eric Miller writes: > re section 3.2.4 > The Dublin Core Initiative has indeed agreed upon a set of formal and > agreed upon relationships for relating resources http://dublincore.org/dcregistry/detailServlet?reqType=detail&item=http%3A%2 F%2Fpurl.org%2Fdc%2Felements%2F1.1%2Frelation > btw... this service is one of several examples that are identified in > section 4.4 > the point being made in the paragraph is an important one, but the > specific example is not correct. Eric, if I understand correctly this is the paragraph you think is incorrect: "Mapping between different schemas This is more difficult than the schema versioning case since often times different versions of the same vocabulary use common conceptualization but this is not often true for different schemas. For example, Dublin Core has an "item-centric" perspective on what is being described, with the majority of the metadata pertaining to the item as a whole, while other descriptive metadata schemas (e.g. the VRA Core schema) describe a conceptual "work" and have many elements for describing details of the described item as well as the whole item. Mapping between Dublin Core and VRA Core schemas is thus challenging because of their different conceptualizations of what is being described, and the different levels of granularity with which they describe things. Another example is Dublin Core versus a recently developed schema for describing biomedical images which takes as it's root the research project which produced the images, and has in its hierarchy the concepts of "study", "instrumentation", and finally the images themselves. Mapping between a flat, one-size-fits-all schema like Dublin Core and something like this biomedical image schema is simply useless, since the metadata about the images themselves is meaningless outside the context of the other project metadata for which there is no equivalent in the Dublin Core schema. So although users may try to encode relationship information, they may not do it in a consistent way. Clearly, just as when mapping between different vocabulary versions, there are situations where it will be possible to perform automatic mapping and situations where there is insufficient information or the information is sufficiently ambiguous to require human intervention. However, arguably, due to the difference in conceptualizations, mapping between schemas is more likely to require the later than mapping between different vocabulary versions." Now in fact this paragraph was proposed by MacKenzie (issue 23). The original text for section 3.2.4 was "Mapping between different schemas This is more difficult than the versioning case as generally different versions of the same vocabulary will use common conceptualization but this is not necessarily true for different schemas. For example, METS can define relationships between different resources. For example it is possible to imagine a resource that is a picture, then a resource that is a photographic reconstruction of that picture, then a resource that is a critical text about the photograph. However other schemas, such as Dublin Core, do not have formal ways of defining such relationships. The DC specification says: "The present resource may be derived from the Source resource in whole or in part. Recommended best practice is to identify the referenced resource by means of a string or number conforming to a formal identification system" So although users may try to encode relationship information, they may not do it in a consistent way. Clearly, just as when mapping between different vocabulary versions, there are situations where it will be possible to perform automatic mapping and situations where there is insufficient information or the information is sufficiently ambiguous to require human intervention. However, arguably, due to the difference in conceptualizations, mapping between schemas is more likely to require the later than mapping between different vocabulary versions." thanks, best regards Dr Mark H. Butler Research Scientist HP Labs Bristol mark-h_butler@hp.com Internet: http://www-uk.hpl.hp.com/people/marbut/
Received on Monday, 7 April 2003 07:10:47 UTC