1. Status on the Mapping of Metadata Standards
ISO/IEC 11179, SDMX, and Others
Arofan Gregory, Executive Manager
Open Data Foundation, Inc.
METIS Meeting, Luxembourg,
April 9-11, 2008

2. Overview Introduction The Mapping Challenge Status of the Mappings
On-Going Work
Summary

3. Introduction
METIS 2006: Several presentations were given addressing some standards mappings
Many side-discussions among attendees
Standards of note included:
ISO/IEC 11179
Statistical Data and Metadata Exchange (SDMX)
Data Documentation Initiative (DDI)
ISO (geographic metadata)
Dublin Core
Extensible Business Reporting Language (XBRL)

4. General Update
There has been informal work to describe the mappings between these standards among individuals from many organizations
Progress is generally good, however…
Very labor-intensive
Not mission-critical for most organizations

5. Initial Approach
After METIS 2006, a general approach for moving forward was identified:
Map all standards against ISO/IEC 11179, so it acts as a pivot
This approach has been largely successful
Not always sufficient for all purposes
Some standards address issues which ISO/IEC does not cover
Pivot approach has been supplemented with some direct mappings

6. The Mapping Challenge There are many ways to map different standards
As with many technology applications, the criteria for success lies in the answer to the question:
“What am I trying to achieve?”
Much work has been done in defining use cases which can serve as the basis for producing mappings between standards

7. High-Level Vision – Standards Mappings
Federated Registries (Based on SDMX, ebXML, web services)
ISO
11179
Semantic
definitions
Aggregated
Data/Metadata
(SDMX)
registered
Organized
using
References to source data
METS Packaging
XBRL
Business
Reports
DDI
Microdata
Sets
Standard
classifications
Dublin Core
Citations
Used in
ISO 19115
Geographies

8. Use Cases The preceding picture embodies several use cases:
Register microdata sets and their metadata (XBRL, DDI, etc.)
Query for microdata/metadata
Capture ISO/IEC metadata for SDMX/DDI/XBRL objects (concepts, codes, etc.)
Query for ISO/IEC metadata on an SDMX object
Link from SDMX aggregates to DDI/XBRL sources
Etc.

9. What Does This Look Like?
Demo of DDI – SDMX Integration

10. Starting Point: Mappings
Five mappings have been identified as a good starting point:
SDMX – ISO/IEC 11179
DDI – ISO/IEC 11179
XBRL – ISO/IEC 11179
SDMX – DDI
XBRL - SDMX

11. SDMX – ISO/IEC 11179 Many false starts – this is a difficult one!
Emphasis is on integration of SDMX mechanisms and ISO/IEC metadata
SDMX does not cover the same detail as ISO/IEC 11179, but provides points of contact (eg, code lists and other representations, classifications, concepts)
This mapping is important to the ISO acceptance of SDMX version 2.0 Technical Specifications
A detailed draft is currently being developed

12. SDMX and ISO/IEC 11179 SDMX Structure Definition
SDMX Structure Components
SDMX Representation
Value Domain
Dimension
Attribute
permissible content
Measure
permissible content
enumerated or non enumerated values
takes semantic from a concept
link to
Permissible Value
link to
SDMX Concept
ISO/IEC Concept
enumerated domains have value meaning
SDMX Code List
ISO/IEC Data Element Concept
ISO/IEC Data Element
Value Meaning 12

13. Prototype
There is an on-going prototype describing the ISO/IEC model as an SDMX Reference Metadata Structure
This will greatly simplify the integration of SDMX and ISO/IEC systems
The SDMX Registry could serve as a basic ISO/IEC Registry implementation

14. DDI – ISO/IEC 11179
DDI has always been oriented toward the ISO/IEC model
Concepts, codes/representations, categories, etc. are similar
The version 3.0 release of DDI is in final voting stages
It can act as an XML-syntax implementation of ISO/IEC for concept banks
This is not mandatory, but it is possible
A detailed draft is being developed

15. DDI 3.0 and
ISO/IEC 11179

16. SDMX - DDI DDI and SDMX have some degree of overlap
Both describe multi-dimensional data cubes
Both have code lists and concepts, etc.
Both provide XML formats for the data and metadata
DDI is oriented toward micro-data, SDMX is oriented toward aggregates
The correspondences based on ISO/IEC cover much of the mapping (codes, concepts, etc.)
Higher-level use of concepts and codes/representations in data and metadata structures requires a dedicated mapping
A detailed draft is being prepared

17. Prototyping
An on-going prototype is being developed to derive SDMX data structure definitions from DDI metadata
This will allow for both aggregates and micro-data documented in DDI to be automatically expressed as SDMX
Micro-data has limited dimensionality
SDMX tools for data visualization, etc., could directly leverage DDI-documented data sets based on a standard transformation
Still in early stages

18. SDMX – XBRL SDMX and XBRL have different applications
XBRL is for individual business reports
SDMX is for aggregates
Both cover multi-dimensional data
SDMX Sponsors and XBRL International have agreed to define a standard mapping
Work is progressing well, and further meetings are expected in 2008
To follow progress, see

19. XBRL – ISO/IEC 11179
Theoretically, an XBRL taxonomy could be described according to the ISO/IEC model, but…
No progress has been made in this area

20. Other Mappings/Notes
Dublin Core and ISO can be described in SDMX as a reference metadata structure
These are both integrated into the DDI 3.0 design
Native Dublin Core XML is supported
Links to ISO compliant shape files are supported
More work is needed here
But not highest priority

21. On-Going Work
4 of 5 mappings should emerge in 2008 as drafts for review:
ISO/IEC – SDMX
ISO/IEC – DDI
SDMX – DDI
SDMX – XBRL
Interesting protoypes/examples are being developed
This includes some prototype tools for performing cross-walks

22. Support and Interest
Generally, support and interest has been very good
Many individuals/organizations have participated informally: METIS, SDMX Sponsors, XBRL International, ISO committees (Open Forum for Metadata Registries), Open Data Foundation, DDI Alliance, NSOs
Standards organizations understand the need to provide alignments and mappings, to support their users

23. Summary Overall progress has been good METIS can help this work
By providing critical feedback on published drafts
By providing visibility and credibility to the results through inclusion in the metadata framework