Topic: Attributes of DCMI Terms ("Usage Board profile") Modified: DATESTAMP Maintainer: Tom Baker Latest version: http://www.bi.fhg.de/People/Thomas.Baker/ISSUES/profiles-usageboard/ Shepherd: Tom Discussion in Shanghai: In Shanghai, I would like to briefly discuss the following issue in order to define a process for moving this forward. At a minimum, I would like to determine the extent to which these issues should be decided in the Usage Board (as opposed to DC-Architecture or the Directorate). We will not have time in Shanghai to discuss any of these points in detail, so UB members need not read the following as carefully as they might have otherwise. At a most general level, I would like to know how urgent we feel it is to clarify aspects of this problem. Summary of the issue: The issue of "DCMI terms describing DCMI terms" has been on the back burner for a long time. We have already in effect defined more than two dozen metadata terms describing various attributes of metadata terms (Name, Label, Definition; types of Status; etc...). However, we have merely documented these terms in Web pages [1,2] -- never have we "declared" the terms formally or assigned them URI references backed by DCMI Namespace Policy. For the purpose of the RDF schemas, we have mapped the handful of attributes most needed for the schemas to existing terms (e.g., in the rdfs namespace maintained by W3C). We need both to clarify both the status of these terms (perhaps taking the occasion to clean up some of the definitions) and the policy by which the terms will be maintained (if different from the existing DCMI Namespace Policy). We also need to consider whether the terms should be assigned URIs and documented in RDF schemas, as other DCMI metadata terms already are. According to my notes, we discussed this issue briefly in Ithaca in 2003 and concluded that the following steps would be involved: 1. Define the set of properties and encoding schemes for describing terms. 2. Understand how they relate to existing terms. 3. Ask DCMI Directorate for UB namespace. 4. Set up UB namespace and declare terms as necessary. 5. Define an application profile. At present, the terms we use are defined in the introductions of two documents - the consolidated document "DCMI Metadata Terms" [1] and the historically complete "DCMI Metadata Terms: a complete historical record" [2]. I have attached a summary of the terms and their definitions below. I currently see the following issues: 1) We need to look carefully at the RDF schema binding to determine which of the attributes used in [1] and [2] are really needed in the RDF schemas. From my notes, here is a draft mapping, with reference to a hypothetical namespace "dcu:" to hold terms not yet formally declared: Name: NOT USED Namespace: rdfs:isDefinedBy rdf:resource="xxx" Label: rdfs:label xml:lang="en-US" Definition: rdfs:comment xml:lang="en-US" Type of term: rdf:type rdf:resource="http://.../#element" Status: dcu:status rdf:resource="http://.../#recommended" Date issued: dcterms:issued Comment: dc:description xml:lang="en-US" See: rdfs:seeAlso rdf:resource="http://..." References: dcterms:references rdf:resource="http://.../#W3CDTF" Refines: rdfs:subPropertyOf Qualifies: dcu:qualifies Date modified: dcq:Modified Decision: dcu:decision rdf:resource = "uri" Version: dcu:version rdf:resource = "uri" Replaces: NOT USED Is Replaced By: NOT USED Broader Than: NOT USED Narrower Than: rdfs:subClassOf Of course, we need to consider the possibility that not all of the attributes of [1] and [2] would be needed in the RDF schemas. 2) If we accept the mappings of some terms defined in [1] and [2] to existing terms in namespaces maintained by W3C and to DCMI's own Terms namespace, then at a minimum it would appear we would need to declare the following: dcu:status - Harry needs this for the DCMI Registry dcu:qualifies dcu:decision dcu:version 3) In addition, it would appear we need the term dcu:isTranslationOf Harry needs this for the DCMI Registry, and Tom thinks this is needed so that a translation of DCMI term definitions into languages such as Japanese can reference the specific Term Version used as the basis for the translation. 4) The term dcu:status has, in effect, a controlled vocabulary of values: http://dublincore.org/usage/documents/process/#conforming http://dublincore.org/usage/documents/process/#recommended http://dublincore.org/usage/documents/process/#registered These are currently defined in the document DCMI Usage Board Process, and the URIs are anchors to specific points in that document. We should consider whether it is a good idea to continue this or whether we would want to declare a status vocabulary, and if so, how their URIs should be formed. 5) The term "Type of Term" (currently mapped in the RDF binding to rdf:type) also has, in effect, a controlled vocabulary of values: http://dublincore.org/usage/documents/principles/#element-refinement http://dublincore.org/usage/documents/principles/#element http://dublincore.org/usage/documents/principles/#encoding-scheme http://dublincore.org/usage/documents/principles/#vocabulary-term 6) Work on the DCMI Abstract Model [3] and a formal model for DCMI Application Profiles [4] suggests a need for several other terms, along the lines of: dcu:ApplicationProfile dcu:PropertyUsage In September 2004, Pete posted a strawman set of terms at http://homes.ukoln.ac.uk/~lispj/cen-cwa/vocab/dcapterms.rdf. 7) DCMI's RDF schemas [5] have long asserted the existence of URI references for terms based on the DCMI Namespace http://purl.org/dc/terms/ -- even though, technically, this should not have been possible without going through UB process. These include: http://purl.org/dc/terms/DateScheme http://purl.org/dc/terms/FormatScheme http://purl.org/dc/terms/IdentifierScheme http://purl.org/dc/terms/LanguageScheme http://purl.org/dc/terms/SpatialScheme http://purl.org/dc/terms/SubjectScheme http://purl.org/dc/terms/TypeScheme We would need to formulate a policy for creating, maintaining, and identifying such terms - bearing in mind that the terms above are already "legacy" (i.e., for all we know, there may be applications in the world that would break if DCMI were to drop or deprecate these terms). 8) Since the addition of http://purl.org/dc/dcmitype/MovingImage http://purl.org/dc/dcmitype/StillImage we have two new attributes for Vocabulary Terms: Broader Than Narrower Than - currently represented with rdfs:subClassOf ------------------------------------------------------------------------ Usage Board Application Profile (draft) ------------------------------------------------------------------------ Mandatory Name [1] The unique token assigned to the term. URI [1] The Uniform Resource Identifier used to uniquely identify a term. Namespace [2] The Uniform Resource Identifier of the namespace within which the term is defined. Label [1] The human-readable label assigned to the term. Definition [1] A statement that represents the concept and essential nature of the term. Type of term [1] The type of term, such as Element or Encoding Scheme, as described in the DCMI Grammatical Principles. Status [1] Status assigned to term by the DCMI Usage Board, as described in the DCMI Usage Board Process. Date issued [1] Date on which a term was first declared. When appropriate Comment [1] Additional information about the term or its application. See [1] A link to authoritative documentation. References [1] A citation or URL of a resource referenced in the Definition or Comment. Refines [1] A reference to a term refined by an Element Refinement. Qualifies [1] A reference to a term qualified by an Encoding Scheme. Broader Than [1] A reference from a more general to a more specific Vocabulary Term Narrower Than [1] A reference from a more specific to a more general Vocabulary Term Version-related Date modified [2] Date on which a term declaration was subsequently modified. Decision [2] A link to the Usage Board decision describing the creation or modification of a term declaration. Version [2] An historical version of a term declaration. Replaces [2] A reference to the immediately precedent historical version of a term declaration. Is Replaced By [2] An identifier for the historical version of a term declaration by which this historical version is superseded. REFERENCES [1] http://dublincore.org/documents/dcmi-terms/ [2] http://dublincore.org/usage/terms/history/ [3] http://www.ukoln.ac.uk/metadata/dcmi/abstract-model/ [4] ftp://ftp.cenorm.be/public/ws-mmi-dc/mmidc116.htm [5] http://dublincore.org/2003/03/24/dcq [6] http://homes.ukoln.ac.uk/~lispj/cen-cwa/vocab/dcapterms.rdf ------------------------------------------------------------------------ Strawman vocabulary drafted by Pete Johnston, July 2004 -- http://homes.ukoln.ac.uk/~lispj/cen-cwa/vocab/dcapterms.rdf about a hypothetical http://example.org/dcap/ ------------------------------------------------------------------------ dcap:SchemaDocument http://example.org/dcap/ dc:title Schema for the DCAP vocabulary dc:description This schema contains descriptions of the DCAP terms. Terms are declared using RDF Vocabulary Description Language (RDF Schema). dc:publisher http://www.ukoln.ac.uk/# dcap:MetadataVocabulary http://example.org/dcap/# dc:title The DCAP Vocabulary dc:description The DCAP Vocabulary provides classes and properties used to describe Dublin Core Application Profiles and Property Usages and related resources. dc:publisher http://www.rdn.ac.uk/# dcap:seeAlso http://www.ukoln.ac.uk/projects/iemsr/wp2/dcap/ dcap:preferredXMLNamespaceName dcap dcap:preferredXMLNamespacePrefix http://example.org/dcap/ rdfs:Class http://example.org/dcap/Document Label: Document rdfs:Class http://example.org/dcap/SchemaDocument Label: Schema Document rdfs:Class http://example.org/dcap/Agency Label: Agency rdfs:Class http://example.org/dcap/MetadataVocabulary Label: Metadata Vocabulary rdfs:Class http://example.org/dcap/AppProfile Label: Application Profile rdfs:Class http://example.org/dcap/PropertyUsage Label: Property Usage rdfs:Class http://example.org/dcap/BindingSchema Label: Binding Schema rdfs:Class http://example.org/dcap/VocabStatus Label: Vocabulary or Profile Status dcap:VocabStatus http://example.org/dcap/VocabStatus/private Label: Private dcap:VocabStatus http://example.org/dcap/VocabStatus/draft Label: Draft dcap:VocabStatus http://example.org/dcap/VocabStatus/proposedRecommendation Label: Proposed Recommendation dcap:VocabStatus http://example.org/dcap/VocabStatus/recommendation Label: Recommendation rdfs:Class http://example.org/dcap/TermStatus Label: Vocabulary or Profile Status dcap:TermStatus http://example.org/dcap/TermStatus/private Label: Private dcap:TermStatus http://example.org/dcap/TermStatus/unstable Label: Unstable dcap:TermStatus http://example.org/dcap/TermStatus/testing Label: Testing dcap:TermStatus http://example.org/dcap/TermStatus/stable Label: Stable dcap:TermStatus http://example.org/dcap/TermStatus/deprecated Label: Deprecated rdfs:Class http://example.org/dcap/Obligation Label: Obligation dcap:Obligation http://example.org/dcap/Obligation/reserved Label: Reserved dcap:Obligation http://example.org/dcap/Obligation/optional Label: Optional dcap:Obligation http://example.org/dcap/Obligation/recommended Label: Optional (Recommended) dcap:Obligation http://example.org/dcap/Obligation/mandatory Label: Mandatory rdf:Property http://example.org/dcap/uses Label: Uses rdfs:range http://www.w3.org/1999/02/22-rdf-syntax-ns#Property rdf:Property http://example.org/dcap/encodingScheme Label: Encoding Scheme rdf:Property http://example.org/dcap/obligation Label: Obligation rdfs:range http://example.org/dcap/Obligation rdf:Property http://example.org/dcap/condition Label: Condition rdf:Property http://example.org/dcap/maxOccurs Label: Maximum Occurrences rdf:Property http://example.org/dcap/isMemberOf Label: Is Member Of rdf:Property http://example.org/dcap/seeAlso Label: See also rdfs:range http://example.org/dcap/Document rdf:Property http://example.org/dcap/version Label: Version rdf:Property http://example.org/dcap/status Label: Status rdf:Property http://example.org/dcap/isExpressedBy Label: Is Expressed By rdfs:range http://example.org/dcap/BindingSchema rdf:Property http://example.org/dcap/preferredXMLNamespaceName Label: Preferred XML Namespace Name rdf:Property http://example.org/dcap/preferredXMLNamespacePrefix Label: Preferred XML Namespace Prefix ----------------------------------------------------------------- 5. Attributes for describing DCMI Terms ("UB application profile") -- Properties for Describing Terms [Tom]: At some point, we should formally declare terms such as "Status" (as well as the Status types: "recommended", "conforming"...). ACTION: Tom to explore possibility of coordinating with SKOS community in this regard. Berlin conference in April will provide opportunity to speak with ISO11179 community as well; will report on results in May.