Not a silly question at all - my current work is just addressing XML, not
RDF; further work on RDF is planned, probably later this year, and hopefully
building on the work you cite below.
There need to be ways of doing e-GMS in XML without using RDF since RDF
would be one heck of an additional training requirement for many of the
folks involved. Hopefully it will all interoperate nicely in the end!
Ann W.
-----Original Message-----
From: DCMI Architecture Group [mailto:[log in to unmask]]On
Behalf Of Eric Miller
Sent: 18 July 2002 18:11
To: [log in to unmask]
Subject: Re: Proposed XML schema for qualified Dublin Core
Hi Ann,
Thanks for the additional reference... This may be a somewhat silly
question, but how does this work cited related to the following?
[[
We have created a schema for UK government metadata which validates
RDF/XML passed to us in an XML sense. We have posted this on the UK
Government Govtalk site for comments.
This schema specifies Dublin Core and EGMS metadata formats in
RDF/XML. Here is the link to it.
http://www.govtalk.gov.uk/e-gov/consult_subject_document.asp?docnum=578
]] - http://groups.yahoo.com/group/jena-dev/message/1375
This work seems to strike a useful balance between syntactic validation
and extensibility for supporting UK government metadata.
--
eric miller http://www.w3.org/people/em/
semantic web activity lead http://www.w3.org/2001/sw/
w3c world wide web consortium http://www.w3.org/
On Thu, 2002-07-18 at 08:53, Ann M Wrightson wrote:
> There is work in progress to define an XML representation for the UK
> e-Government Metadata Standard (e-GMS). The specification will probably be
> out for consultation on the UK GovTalk website c. mid-August
> (http://www.govtalk.gov.uk); in the meantime, it may be useful for you to
> have this extract (below) from the current working draft (0.3), which
> describes the design criteria and rationale.
>
> Regards,
>
> Ann W.
>
>
> Ann M Wrightson MA MBCS
> Prif Ymgynghorydd / Principal Consultant
> alphaXML Cyf/Ltd
> http://www.alphaxml.com
> Gwasaneuthau XML: e-Lywodraeth, e-Fasnach, e-Gyhoeddi
> XML services to Government and Industry
>
> Representing e-GMS metadata in XML
> DRAFT
> Extract for DC & DSDL comment 18 Jul. 02
>
> Document version 0.3
>
> 1.2 Background
> The e-Government Metadata Standard is technology-independent. Amongst
other
> representations, e-GMS metadata will certainly occur in XML, for example,
> in XML messages containing metadata, and in XML documents with embedded
> metadata. e-GMS metadata in XML is likely to occur in a number of
different
> contexts, including:
> * embedded within XML schema documents (prepared according to W3C XML
> Schema Recommendation 2001)
> * embedded within XML documents fulfilling specific functions, eg public
> records, and reports submitted for specific regulatory purposes
> * information exchanged using an XML message includes e-GMS metadata
about
> something outside the message
> * within a dedicated metadata repository
> * as a block of descriptive metadata within a wider metadata framework
such
> as the Metadata Encoding and Transmission Standard (METS)
> * supplementary metadata attached to an existing XML document, eg
metadata
> created when a record is selected for long term preservation; or metadata
> pertaining to the role of a pre-existing document within a set of
documents
> collected for a Public Inquiry.
> 1.3 Key design issues for XML representation of e-GMS metadata
> This section discusses key design issues, and lists the design criteria
for
> the XML representation of e-GMS metadata arising out of the issues.
> In the lists of design criteria, "e-GMS-XML" is used as a short form of
"an
> XML representation of general-purpose e-GMS metadata"; and "W3C
> Schema-validation" for "validation according to W3C XML Schema
> Recommendation 2001".
> 1.3.1 Long life of metadata
> e-GMS metadata can be expected to be long-lived, and contribute to the
> management, discovery and utilization of electronic resources over a long
> life for the resource (eg >100 years for an e-archive of electronic
public
> records). XML is an ISO standard as well as a widely adopted industry
> standard, and a successor to a very similar standard already 25 years
old -
> and so is very likely to be long-lived. W3C XML Schema, although a good
> choice at present for schema definition within e-GIF, is less likely to
be
> long-lived, since there are competing schema languages for XML (which may
> in future gain wider industry acceptance). In addition, an ISO XML schema
> standard is under development, which is intended to encompass and
harmonize
> current approaches into a long-lived stable standard.
> Bearing all this in mind, it is advisable for the XML representation of
> general-purpose e-GMS metadata to be independent of specific features of
> W3C schema-validation, whilst also being compatible with the immediate
> e-GIF requirement to validate XML by this means.
> XML is likely to be long-lived. However, some public sector documents
have
> a very long projected lifetime, and it is unlikely that XML will remain
the
> standard of choice for interoperability over all that time. The nature
and
> wide adoption of XML makes it unlikely that document content in XML will
> become unusable, since XML viewing applications are likely to remain
> available in the long term. However, the principal utility of metadata is
> in its daily use to support integrated access to current and past
> information resources, so it is quite likely that metadata in XML will
> eventually become functionally obsolete. Because of this, e-GMS metadata
in
> XML should be easy to convert to a successor data format.
> Design criteria:
> * e-GMS-XML does not depend on specific features of W3C
Schema-validation,
> but rather uses XML structures which are likely to be straightforward to
> validate using any future XML schema language
> * e-GMS-XML is compatible with the immediate e-GIF requirement to
validate
> XML documents and messages using W3C Schema-validation
> * e-GMS-XML is likely to be easy to translate into a future successor
> format to XML
> 1.3.2 Compatibility with Dublin Core
> The e-GMS metadata standard is based on Dublin Core. Standardized XML
> representation of Dublin Core metadata is currently under development in
> DCMI. The design criteria and principal scenarios of use for metadata are
> different between DCMI and UK Government; this is already evident in the
> e-GMS itself, where some aspects depart from DCMI principles. Because of
> this, simple adoption of the Dublin Core XML representation for e-GMS is
> unlikely to be appropriate. However, it is highly desirable that
> interoperation between e-GMS metadata and generic Dublin Core metadata
> should be easy to achieve - if that were not so, then the main intended
> benefit of basing e-GMS on Dublin Core would be lost.
> The concept of "dumb-down" use of metadata is important for
> interoperability between metadata-aware applications with different
> capabilities. The key point is that when any metadata processor looks at
a
> set of metadata, it should be able to identify and use all the metadata
> elements which it can understand. In particular, refinements which it
does
> not understand can be ignored, and the value of an element refinement
used
> as if it were the unrefined element.
> In general, "dumb-down" is a forgetful yet faithful metadata translation,
> preserving faithfully from a more expressive metadata form all & only
what
> a less expressive metadata form can express. In the context of e-GMS,
> "dumb-down" metadata processing is likely to have two forms: processing
> metadata devised according to an e-GMS local metadata standard as if it
> were generic e-GMS metadata; and processing e-GMS metadata of any kind as
> if it were simple Dublin Core.
> Design criteria:
> * e-GMS-XML can be mapped to the Dublin Core standardized XML
> representation in a straightforward manner, for those metadata elements
> common to e-GMS and Dublin Core. This provides a proper "dumb-down"
> metadata mapping of e-GMS to Dublin Core.
> * e-GMS-XML supports "dumb-down" processing of metadata conforming to an
> e-GMS local metadata standard as if it were generic e-GMS metadata, in a
> uniform and straightforward manner.
> 1.3.3 Interdependency and more complex constraints on metadata elements
> e-GMS metadata has constraints on the optionality and interdependency of
> its elements, and some of these constraints are not suitable for direct
> validation using W3C Schema-validation. The ISO schema standard under
> development is intended to support more of this kind of functionality,
but
> it is not yet clear whether this will gain widespread industry support.
> There are also a number of industry standards and initiatives providing
> capabilities in this area. Just as for the ISO standard, the nature and
> depth of industry support for these approaches in the medium term is
> uncertain.
> Local metadata standards based on e-GMS are likely to introduce more of
> these kinds of constraints, since metadata will be used to represent data
> pertaining to business rules. XML validation is principally designed to
> validate the structure of an XML document, and the data type of XML
element
> content. However, these capabilities are often used to enforce business
> rules, and it is widely seen as a virtue that XML validation should
extend
> as far as possible in this direction. This situation makes it difficult
to
> be precise about a suitable boundary between XML validation and
> supplementary validation for metadata.
> Design criteria:
> * where e-GMS-XML requires validation over and above validation of the
> structure and data type of the XML, this is simple, and specified in a
> technology-independent manner
> * where these more complex constraints are supported by widely used XML
> technologies, then guidelines and best practice on using these should be
> provided
> 1.3.4 Interoperability between XML metadata technologies
> XML metadata is an area where there are a number of standards, and these
> standards tend to be complementary rather than competing (though they may
> be competitors in the context of a specific application). The picture is
> made more complex by the fact that these standards come from different
> domains only now converging through the ubiquity of Internet technology -
> for example, there are well-regarded standards with origins in
> librarianship and information science (Dublin Core), artificial
> intelligence (DAML/OIL), and electronic publishing (ISO 13250 Topic
Maps),
> together with efforts to integrate the metadata domain in its own right
> (ISO 11179, METS), as well as the ongoing work in W3C.
> Although it is desirable to have a uniform XML representation of e-GMS
> metadata, it is also important to enable Government organizations to
choose
> freely between technology solutions based on different industry
standards.
> This is particularly important since some Government organizations have
> close ties to specific industry sectors. An important first step has
been
> taken by making the e-GMS standard itself technology independent.
> At one extreme, fine-tuned XML representations of e-GMS metadata could be
> devised for each specific context, using a range of XML metadata
> technologies. However, this would lead to a large number of different
> "standard" representations, and discourage easy interoperability. Another
> approach would be to define a rigid "one size fits all" XML
representation.
> Neither of these is likely to meet the practical requirements of
Government
> organizations. The design criteria below are intended to offer a
reasonable
> middle way.
> Design criteria:
> * e-GMS-XML provides datatype definitions for e-GMS metadata element
> values. These will be a common resource for all e-GMS XML
representations.
> * e-GMS-XML provides a representation designed for use in an e-GIF XML
> message containing metadata about something outside the message. This is
> the most general form of e-GMS metadata in XML, designed to accommodate
any
> (technology independent) e-GMS local metadata standard, and thus
providing
> a simple basis for interoperability between any e-GMS complaint systems.
> * e-GMS-XML provides a representation designed to sit within the context
of
> an XML document. This could be within the XML data for a publication (eg
a
> report), or within another XML context such as a METS descriptive
metadata
> section.
> * e-GMS-XML provides guidelines and examples for using e-GMS with
selected
> XML metadata technologies. The aim of these guidelines is to support, for
> example, easy interoperability in RDF between e-GMS compliant systems
using
> RDF. These guidelines are expected to evolve over time, as specific XML
> metadata technologies gain and lose acceptance in the marketplace.
> * e-GMS-XML provides guidelines for designing XML representations of
e-GMS
> local metadata standards (it is envisaged that the e-GMS XML schema local
> metadata standard will be updated to conform to these guidelines in due
> course).
> 2 Requirements for Implementation
> The utility of this specification depends on the availability of
> standardized value sets and notations to provide commonly understood
> meanings for the metadata element values. This requirement is a general
one
> for metadata. However, there is also a more precise requirement for the
XML
> representation of e-GMS metadata.
> The standardized value sets and notations used in e-GMS metadata must
have
> concise names suitable for use as XML attributes. These names must be
> persistent, that is, they must be as far as possible guaranteed to retain
> their significance for as long as the metadata is expected to be retained
> (including possible preservation as a public record).
> The following are NOT suitable for use as names for value sets and
> notations in this context:
> * URLs or URIs, unless specifically designed for the purpose and
guaranteed
> by a long-lived and trusted authority
> * An XML schema namespace name (it is a technology-specific surrogate for
> the notation name).
> It is recommended that standardized value sets and notations used in
e-GMS
> metadata are administered in a registry designed for long-term
persistence
> as a reference for understanding e-GMS metadata. The persistence and
> integrity of this registry is essential for the accessibility and
usability
> of Government information in the long term.
> 3 References
> 1
> e-Government Interoperability Framework (e-GIF) v4
> http://www.govtalk.gov.uk/interoperability/egif_document.asp?docnum=534
> 2
> e-Government Metadata Standard v1.0 April 2002
> http://www.govtalk.gov.uk/interoperability/metadata_document.asp?docnum=
524
> 3
> e-Government Local Metadata Standard for XML Schemas v1.0 May 2002
> GSG paper Q2 2002
> 4
> e-GIF XML Architecture
> GSG paper Q1 2002
> 5
> Resource Description Framework (RDF)
> http://www.w3.org/RDF/
> 6
> Government Data Standards Catalogue (GDSC), all volumes
> http://www.govtalk.gov.uk/interoperability/eservices.asp?order=title
> 7
> Metadata Encoding and Transmission Standard (METS)
> http://www.loc.gov/standards/mets/
> 8
> Dublin Core Metadata Initiative work in progress
> http://www.ukoln.ac.uk/metadata/dcmi/xmlschema/
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