240 likes | 501 Views
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. Overview. Introduction The Mapping Challenge Status of the Mappings On-Going Work Summary.
E N D
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
Overview • Introduction • The Mapping Challenge • Status of the Mappings • On-Going Work • Summary
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 19115 (geographic metadata) • Dublin Core • Extensible Business Reporting Language (XBRL)
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
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 11179 does not cover • Pivot approach has been supplemented with some direct mappings
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
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
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 11179 metadata for SDMX/DDI/XBRL objects (concepts, codes, etc.) • Query for ISO/IEC 11179 metadata on an SDMX object • Link from SDMX aggregates to DDI/XBRL sources • Etc.
What Does This Look Like? Demo of DDI – SDMX Integration
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
SDMX – ISO/IEC 11179 • Many false starts – this is a difficult one! • Emphasis is on integration of SDMX mechanisms and ISO/IEC 11179 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
SDMX and ISO/IEC 11179 SDMX Structure Definition SDMX Structure Components SDMX Representation Value Domain Dimension permissible content Attribute Measure permissible content enumerated or non enumerated values takes semantic from a concept link to Permissible Value link to SDMX Concept ISO/IEC 11179 Concept enumerated domains have value meaning SDMX Code List ISO/IEC 11179 Data ElementConcept ISO/IEC 11179 Data Element Value Meaning
Prototype • There is an on-going prototype describing the ISO/IEC 11179 model as an SDMX Reference Metadata Structure • This will greatly simplify the integration of SDMX and ISO/IEC 11179 systems • The SDMX Registry could serve as a basic ISO/IEC 11179 Registry implementation
DDI – ISO/IEC 11179 • DDI has always been oriented toward the ISO/IEC 11179 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 11179 for concept banks • This is not mandatory, but it is possible • A detailed draft is being developed
DDI 3.0 and ISO/IEC 11179
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 11179 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
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
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 www.sdmx.org
XBRL – ISO/IEC 11179 • Theoretically, an XBRL taxonomy could be described according to the ISO/IEC 11179 model, but… • No progress has been made in this area
Other Mappings/Notes • Dublin Core and ISO 19115 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 19115-compliant shape files are supported • More work is needed here • But not highest priority
On-Going Work • 4 of 5 mappings should emerge in 2008 as drafts for review: • ISO/IEC 11179 – SDMX • ISO/IEC 11179 – DDI • SDMX – DDI • SDMX – XBRL • Interesting protoypes/examples are being developed • This includes some prototype tools for performing cross-walks
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
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