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Change management documents produced by authoritative providers
Library of Congress
LOC currently implements Activity Stream and has types.ATOM feeds for each of its datasets. Examples:
- Subjects: http://id.loc.gov/authorities/subjects/feed/1
- Names: http://id.loc.gov/authorities/names/feed/1
- Organizations: http://id.loc.gov/vocabulary/organizations/feed/1
- ISO 639-2: http://id.loc.gov/vocabulary/iso639-2/feed/1
This provides information about whether and when resources have been created, updated, or deleted/deprecated.
LOC is in the process of implementing Activity Stream. This work will duplicate the information communicated with the current ATOM feeds, but will also permit LOC to offer more specific activity streams, such as one devoted solely to authoritative label changes. Some issues being considered:
- URI URI belongs to a scheme when active (e.g. subject scheme). This is identified by a triple. The scheme triple is removed when it is deprecated. Point is: Deprecation alters the resource in fundamental ways.
- Sometimes a term may move from one authority (e.g. subject) to another (e.g. genre). Adds a triple identifying the new term (e.g. use_instead predicate). Complicated when the change is a split. Which term's URI should be used for use_instead?
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- This makes redirection or advertisement of the 'replacement' URI easy. But sometimes a single term may be split into two or more. No longer a one-to-one replacement, it is unclear what a suitable replacement would be for the old URI.
MeSH
- documents deletions
Getty
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- Keep a copy of the library's authority file. This file may be provided by the library at the beginning of the contract, or built by the vendor by matching headings in bibliographic records against one or more authoritative sources.
- Keep track of all unmatched headings (i.e. headings used in bib records that had no match when last searched) and partial matches (e.g. only the name portion of a name/title heading has a match, or only the main subject heading of a main plus subdivision(s) heading has a match)
- Monitor changes in the authoritative source (i.e. new additions, change of an existing record, deletion or deprecation of an existing record)
- Based on this monitoring, provide an updated record when a record that is in the library's authority file has changed.
- At a specified period (e.g. every three months) re-search all previously unmatched headings against the latest version of the authoritative source to see if there is now a match. If so, provide the matching "new" record to the library or have the have library send the bib records with that heading for re-processing.
- At a specified period (e.g. every three months) re-search all previous partial matches against the latest version of the authoritative source to see if there is now a full match. If so, provide the full match record or have the library send bib records with the partial match for re-processing
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