ADN metadata history: going from DLESE-IMS to ADN
A timeline of past developments (1999 to 2003)
The DLESE metadata group started in late 1999. Because education about the Earth system is a driving factor, DLESE wanted to ensure whatever metadata framework it adopted or developed included educational metadata. Since Earth science is strongly geospatially and temporally situated, these concepts are of importance too. However, they are secondary when compared to educational information.
To address these metadata needs, DLESE began looking at FGDC, Dublin Core (simple and qualified) and IMS. Because FGDC did not have the educational metadata that DLESE was looking for, that framework was not adopted. Since both Dublin Core and IMS showed promise, numerous resources were cataloged in both metadata frameworks to test how educational, geospatial, temporal information played out (from December 1999 to June 2000).
Since simple Dublin Core does not have much in the way of educational, geospatial or temporal information, it was ruled out. Qualified Dublin Core in late 1999 and early 2000 was much weaker than IMS on educational metadata but there was a hint that there would soon be encoding schemes for defining geospatial points and bounding boxes. IMS also hinted at providing encoding schemes for geospatial as well.
At this time, IMS was also offering an XML-based metadata framework while Dublin Core was not. This appealed to DLESE because DLESE wanted to use XML as the basis for the library and accompanying services. Therefore, on June 1, 2000 DLESE adopted IMS as its metadata framework. A few months later, the first DLESE resources cataloged in IMS became available for search and discovery.
To support the next planned versions of the library, there was a push in 2001 for DLESE to collect information about relating educational standards to resources. IMS has a classification scheme that can be used for such taxonomies. IMS also allows users to create their own extensions to the framework following a certain procedure. DLESE found both the classification scheme and adding your own fields clumsy (e.g. when DLESE created the hierarchal resoure type vocabulary). And it was difficult keeping up with the evolving IMS framework as new framework versions were issued. IMS underwent several upgrades in its early stages of existence (when DLESE was using it). IMS still had not yet fully implemented geospatial or temporal information in the framework either.
Since DLESE desired educational standards, geospatial and temporal information immediately, DLESE made the decision to build on the IMS work by creating its own metadata framework called DLESE-IMS. This framework would have the IMS information but sections for educational standards, geospatial and temporal information. This was quickly done to meet DLESE community needs. This framework became operational in August 2001 and was XML DTD-based just like IMS. 2001. The ability to catalog to National Science Education Standards and Geography standards was put in the DLESE cataloging tool by April 2002.
During this time, DLESE was forging partnerships with the Alexandria Digital Library (ADL) and the NASA Earth Science Enterprise (now called Science Mission Direcotrate (Earth-Sun System Mission)). Since certain educational components, geospatial and temporal information was important to all three partners, the trio decided to develop their own metadata framework to address the deficiencies of the quickly thrown together DLESE-IMS framework and to take advantage of XML schema. XML schema has advantages over XML DTD. One idea was that it would allow the framework and controlled vocabularies to be more flexible for the needs of each group. Controlled vocabularies could be in their own XML schemas and sort of plug and played.
From the partnership, the ADN (first letter for each group) framework emerged in March 2003 and was incorporated into DLESE search system in August 2003. Table 1 displays the original IMS educational fields and indicates the reason why the IMS field was retained, retired or a new field was adopted to define the educational fields in the ADN metadata framework. The table does not indicate which groups wanted or needed specific fields.
Table 1. Evolution of Educational Fields from IMS to ADN
Essentially, DLESE now has its own metadata frameworks for cataloging resources. This ADN framework was constructed from the IMS, GEM and Dublin Core fields that worked best for DLESE.
Recent developmenets (2003 and later)
Changes between ADN v0.6.20 and v0.6.50
Last updated: 12-16-04