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ResourceMetadata
Work Package 3 (Rwp03): Metadata Specifications
Contents
Introduction
Members
This WP is led by
RayPlante with
SebastienDerriere,
BobHanisch,
CliveDavenhall,
ClivePage,
ElizabethAuden,
ArnoldRots,
RoyWilliams
Scope
A Resource is any entity that can be described and identified in a
machine readable manner. With this general statement, a resource can
be most anything, including a service or a data collection or
something more abstract, such as a standard interface. In this work
package, we will:
- Identify the pertinent information necessary for describing and locating a resource within a registry, satisifying the requirements set forth in RWP02.
- Provide a basic, extensible data model for describing resources within a registry.
- Develop an XML schema for rendering descriptions of resources in terms of the resource data model.
Although a resource could be anything, this WP should concentrate on
describing high-level entities, such as organizations, data
collections, and services; this is referred to as coarse-grain
granularity. We should strive to keep the basic resource data model
simple, reusing data model components (that might come out of the Data
Models Working Group) where ever possible. At the same time, the data
model needs to provide hooks to allow additional metadata to be
included in order to describe more specific types of resources.
References and Background
From the
Registry Kick-Off Meeting in London, 19-03-2003.
See also the
Registry WG Session Page for the
IVOA Interoperability Workshop held May 12-16, 2003 in Cambridge, England.
Previous Modeling from the NVO:
- Resource Metadata Note: Deprecated by later versions listed in Specifications section below.
Note that the above Schema is under development and changes often. More stable versions should appear under the
Specifications section below.
--
RayPlante - 14 Apr 2003
Previous Modeling by the
AstroGrid Project:
--
RayPlante - 30 Apr 2003
Specifications
This section is for specifications currently under discussion. A spec's inclusion here says nothing about its overall acceptance by the team or community, but rather provides a definitive location for documents under discussion. I recommend that such documents be
uploaded (i.e. attached) and labeled with a version number, and all versions should be preserved and accessible. I recommend the following format:
Example:
--
RayPlante - 14 Apr 2003
Resource (and Service) Metadata (RM)
IVOA Identifiers
- IVOA Identifiers: an IVOA Working Draft. latest version: 0.2 (HTML)
- A compliant XML Schema for the XML format for identifiers: latest version (0.1)
Versions: 0.2, 0.1
- Some strawman ideas for amending the Identifier framework for supporting persistance and location-independence.
VOResource: a Resource Metadata Schema
New as of 18 Nov. 2003.
Developers have identified a few mistakes in the schemas; as a result, the following files have been updated:
Be sure to download these updated versions (or download the complete set from the tar-ball/zip-file links below).
New as of 5 Nov. 2003.
Updated WD versions of the schema are now officially available. Developers should be sure to download the latest versions from the table below (or all of them together:
tar-file,
zip-file)--even the version number appears unchanged--as the namespace names have all been updated. These are the schemas to be used for January 2004 demos.
The schemas are:
The following two extensions are examples of extensions that define
two standard
tabular sky services. They include the elements necessary for decribing the tables returned by the services (using VOTable tags). These are included for indicative purposes only.
Example instance containing several resource descriptions:
Download all schemas in one go; two versions are available below. When these packages are unpacked, all files will be put in the current directory.
- VOResource-v0.9 (tar.gz, zip)
- the official schemas from the table above.
- VOResource-v0.9-local (tar.gz, zip)
- the official schemas with "schemaLocation" set to look for imports on local disk. This version enables a verifier to look for schemas in the current directory instead from the IVOA site. Use this version when developing off-line or with tools that have trouble finding imported schemas.
More supporting material is coming soon!
Deprecated Versions
For more detailed information (particularly if you are not used to looking at XML Schema), please see the following additional resources:
- VOResource Overview (version 0.8.3)
- an overview of the schema containing high-level diagrams, a summary of major changes from the last version, and pointers to more detailed documentation.
- adil-v0.8.3.xml
- an example instance file describing several resources associated with the NCSA Astronomy Digital Image Library (ADIL), including 3 services for accessing the data.
- Schema Documentation
- You can interactive browse automatically generated documentation by following the "XMLSpy" or "xs3p" links in the tables above.
-- RayPlante - 6 October 2003
Below is earlier verisons of VOResource and supporting information that are deprecated by the proposal above. The 2nd schema below holds metadata (roughly) specific to the SIA protocol.
- VOResource.xsd: Versions: 0.1
To help folks interpret these schemas, I've prepared some additional resources:
- An overview document that explains the major components and structure of the schemas; you may find the XMLSpy diagrams particularly helpful. It also gives a summary of the overall approach used to define metadata within XML Schema.
- A sample XML instance document shows how to describe an organization, a data collection, and services using this schema. It shows how metadata from different schemas can be combined into a single document. (See overview document for more description.)
- A Metadata Dictionary generated automatically directly from the XSD file using an XSL stylesheet.
-- RayPlante - 22 Apr 2003
Progress Reports