XML Schema for DC Libraries AP

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XML Schema forDC Libraries AP DC Libraries WG
Meeting, DC-2005,Madrid, Spain, Tuesday 13
September 2005 Pete Johnston Research Officer,
UKOLN, University of Bath
UKOLN is supported by
www.bath.ac.uk
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XML Schema for DC Libraries AP

• XML Schema
• DCMI Abstract Model
• XML Binding for DC
• DC Application Profiles
• XML Schema for DC Lib AP

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XML Schema

• XML Schema describes structure of class of XML
  documents
• names of XML elements/attributes
• constraints on XML element content/attribute
  values
• datatyping for XML element content/attribute
  values
• XML "instance document"
• Schema validation

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XML Schemas for DC Lib AP

• So
• what should be the structure of this class of XML
  documents?
• what XML elements/attributes?
• what content models?
• what datatypes?
• etc etc etc
• What is this XML Schema for?

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Dublin Core is not an XML format
lt?xml version"1.0" encoding"UTF-8"?gt ltmyDC
xmlnsdc"http//purl.org/dc/elements/1.1/"
xmlnsdcterms"http//purl.org/dc/terms/"
xmlnsmy"http//purl.org/my/"
xmlnsxsd"http//www.w3.org/2001/XMLSchema" gt
ltdctitle xmllang"en"gtMy Thinglt/dctitlegt
ltdcdescription xmllang"en"gtMy thing is a
thingummy.lt/dcdescriptiongt ltdctermscreatedgt200
5-03-15lt/dctermscreatedgt lt/myDCgt
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Dublin Core is...

• a vocabulary/set of terms...
• managed by DCMI (Usage Board)
• defined and used within...
• a conceptual model/framework/set of rules...
• DCMI Abstract Model
• describes how to use these (and other) terms
• ... to make statements...
• ... that form descriptions (of resources)

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Resource URI
Vocab Enc Scheme URI
Syntx Enc Scheme URI
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DCMI Abstract Model and Bindings

• DCAM conceptual model
• types of construct
• relationships between constructs
• Description sets encoded as records
• Binding specification
• mapping between constructs in conceptual model to
  components in syntax
• Two way
• encoding application description set -gt record
• decoding application record -gt description set

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DCMI Abstract Model and XML

• DCMI provides multiple "encoding guidelines"
  specifications
• XHTML, RDF (Simple, Qualified), XML
• Guidelines for implementing Dublin Core in XML
  (2003)
• XML binding for DC metadata
• Other non-DCMI XML bindings for DC deployed
• Mapping between constructs in conceptual model to
  components in XML
• XML elements (names, content),
• XML attributes (values)
• models actually different from DCAM (DC Arch WG)

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DC Application Profile

• Specifies terms used in a class of description
  sets
• Information on how properties applied in context
  of application
• Constraints on occurrence of statements
• Constraints on values (vocabulary encoding
  schemes)
• Constraints on value representations
• value URI
• value string/syntax encoding scheme
• rich representation

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XML Schemas for DC Lib AP

• XML Schema for DC Lib AP should describes
  structure of the class of XML documents that are
  serialisations of DC Lib AP metadata
  descriptions, created according to DC-XML 2003
  binding

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XML Schemas for DC Lib AP

• Schema for "dclib" XML Namespace
• temporary URI for XML Namespace Name
• temporary schemaLocation
• imports DCMI schemas for "dc", "dcterms" XML
  Namespaces
• imports LoC schema for "mods" XML Namespace
  (v3.0)
• declare XML element (dclibdescriptions) to
  represent DCAM description set
• declare XML element (dclibdescription) to
  represent DCAM description

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XML Schemas for DC Lib AP

• Content model for dclibdescription references
  XML elements representing statements
• use of substitution groups in DCMI XML Schemas
  means that reference to property makes all
  subproperties available
• Use of XML Schema datatyping in DCMI XML Schemas
  means can't limit encoding schemes used for
  property
• XML Schema Occurrence/obligation requires
  ordering

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XML Schemas for DC Lib AP

• References to XML element declarations in LoC
  "mods" schema introduces content models from MODS
  XML format
• modslocation (sub-elements modsurl,
  modsphysicalLocation)
• modsoriginInfo (sub-elements modsedition,
  modsdateCaptured)
• Problem
• XML sub-tree constructed according to rules of
  MODS XML format
• XML sub-tree has no interpretation in DC XML
  binding
• XML fragments conforming to different XML formats
  can not generally be merged in this way

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DC and MODS

• MODS-XML is binding for MODS DC-XML is binding
  for DCAM (almost!)
• MODS based on hierarchical data model DCAM based
  on statement model
• MODS "elements" are "containers" DC "elements"
  are properties, types of relationship
• MODS "elements" have attributes DC "elements" do
  not
• MODS "elements" interpreted in context of
  hierarchy DC "elements" interpreted in context
  of DCAM

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DC and MODS

• Need to qualify notion of "element reuse", "mix
  match"
• "Terms" referenced in DC metadata descriptions
  are instances of concepts in DCAM, so...
• ..."terms" referenced in DCAPs must be too
• MODS elements are not
• Need to create new terms which are appropriate
  for use in DC metadata descriptions
• Analyse information conveyed by MODS constructs
• Create properties, vocab encoding schemes etc to
  represent that information
• Assign URIs to those properties, etc

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XML Schema forDC Libraries AP DC Libraries WG
Meeting, DC-2005,Madrid, Spain, Tuesday 13
September 2005 Pete Johnston Research Officer,
UKOLN, University of Bath
UKOLN is supported by
www.bath.ac.uk