- What is CORDRA
- Who is leading CORDRA
- Motivation for CORDRA
- Basic assumptions for CORDRA
- CORDRA in comparison with Google
- Simple search versus federated search
- CORDRA in relation to other initiatives
- CORDRA as an infrastructure
- CORDRA is not a new specification
- SCORM in relation to CORDRA
- Activities planned for CORDRA project
- Where CORDRA registries will reside
- Deciding about getting involved with CORDRA
- CORDRA project status
- Participation in CORDRA activities
- Contact for more information
CORDRA stands for Content Object Repository Discovery and Registration/Resolution Architecture. It is a model of how to enable the next step in the evolution of e-learning, namely, how to solve the problem of finding and reusing learning content.
Its goal is to develop a model for how to do this, using existing technology from the worlds of learning content management and delivery, content repositories, and digital libraries. CORDRA aims to identify and specify (not develop) appropriate technologies and existing interoperability standards that can be combined into a reference model that will enable learning content to be found, retrieved and re-used.
Who is leading the CORDRA project?
Initial efforts in establishing the CORDRA model and prototype registry are being guided by a trio representing three distinct entities: the government (Advanced Distributed Learning Initiative - ADLI), a non-profit corporation (Corporation for National Research Initiatives - CNRI), and academia (Learning Systems Architecture Lab - LSAL).
Because the Department of Defense has an immediate need for such a system, the ADL is currently coordinating the CORDRA project and providing funding for the effort. Philip Dodds of ADL serves as the project's overall director.
CNRI is on board to build the first example of a CORDRA system, an ADL registry. CNRI was the logical choice for this task in light of their experience with digital libraries and identifier systems. Larry Lannom heads the CORDRA prototype effort on behalf of CNRI.
LSAL's contribution to the team is to ensure that the design of CORDRA is technically feasible for global participation over the long term. Dan Rehak from LSAL guides the technical aspects of CORDRA as the lead technical architect.
The plan is to transition CORDRA beyond ADL to include constituencies besides the U.S. government and military (international organizations, K-12, higher education, life learners, etc.).
What was the motivation behind CORDRA?
As the amount of learning content that conformed to the SCORM guidelines grew, several forward-thinking individuals involved in the ADL Initiative realized that all the sharable content objects in the world would not be of much use to organizations beyond those that initially created them unless the content could be discovered, located and retrieved. An infrastructure to support search and retrieval of content does not currently exist.
Anticipating a future desire of the global e-learning community to take advantage of the economy of re-use, the CORDRA project was conceived of by a small group of individuals who had been involved with SCORM and digital object management. They envisioned an infrastructure scheme that was based on registering an organization's content in a way that would facilitate broad reuse of the sharable learning content beyond the original organization.
What are the specific tenets that provide the basis for CORDRA?
Five assumptions provided the initial impetus for the CORDRA project. These led to formal requirements for the capabilities that the CORDRA system would provide.
- After content has been authored, it can be made widely available (subject to appropriate rights management).
- Content can exist and be re-used in pieces smaller than a single course.
- Content can be discovered.
- Once content is discovered, there will be standard ways to get it.
- Different organizations can decide to make their content available in different ways but still be part of the CORDRA approach.
Is CORDRA essentially a search engine similar to Google?
The CORDRA system, like the Google search engine, will rely on a simple search of a catalog of "metadata" to find specific content the instructional designer or other user has requested. Typically, a designer will have a set of requirements for a learning experience and will need content that matches learner-specific criteria.
But Google's search area is limited to what can be found on the Internet: Google does not find content that resides in repositories, nor can it provide content specifically authored for learning. Its index/search functions do not generally rely on formal, authored metadata (such as IEEE Learning Object Metadata).
The CORDRA system will provide a way to search for learning content via the catalogs of authored metadata in the registries. That metadata will include information about the content in repositories that can be used to determine if the content might be appropriate for the targeted learners. If the desired content is discovered, then the CORDRA system can locate the content in the particular content repository in which it is stored. The ultimate retrieval of the found content, however, will be governed by the policies of the repository's owner.
Is simple search of federated metadata the only means of searching multiple repositories?
No. Other groups are investigating methods that employ a federated search across repositories directly. The proponents of CORDRA believe that federating the metadata for content from several repositories via a registration process and then running the search on the combined metadata will avoid problems encountered by processes that attempt a direct search of multiple content repositories.
Why is CORDRA needed in addition to other systems that search for learning content?
The proponents of CORDRA anticipate that the federated search systems used to integrate resource-sharing systems such as MERLOT (Multimedia Educational Resource for Learning and Online Teaching), GLOBE (Global Learning Object Brokered Exchange), and others will ultimately not scale well; CORDRA's backers strongly believe that a search of registered metadata will ultimately prove to be a better method of searching across multiple content repositories. Also, systems like MERLOT have a particular model of what goes into a repository and how it's managed. CORDRA focuses on the federation of the repositories, not on how any single repository operates.
What distinguishes CORDRA as an infrastructure?
Unlike the development of world-wide telephone communications systems in which integrated, networked systems were built in order to connect and merge small, local companies, the CORDRA system for federated content repositories is being planned from the top down to utilize existing local systems. The advantage of this planned infrastructure is that when a community anywhere in the world creates a repository or digital library to house their particular set of content, there will already be a global, federated system that they can join. Of course, the added repository must adhere to the CORDRA rules for registering its content's metadata with a CORDRA registry.
Is CORDRA a completely new specification?
No. As part of the notion of economy of re-use, CORDRA will be based on existing standards for learning content, repositories and digital libraries. The CORDRA project's proponents believe that sufficient standards and technologies exist; what is needed is to utilize them in combination to achieve interoperability.
Thus, while the "blueprint" for the CORDRA model will combine and refine other standards documents as necessary, the CORDRA model should not be regarded as a completely new specification.
How is SCORM related to CORDRA?
The common thread between SCORM and CORDRA is the ADL Initiative's involvement in both models. There is no requirement that CORDRA registries be limited to those content repositories that contain SCORM content, nor is it a requirement that all SCORM-conforming content outside the US DoD be "tagged" for inclusion in a CORDRA registry.
Thus it is merely a historical fact that the ADL Initiative previously oversaw the coalescence of the sharable content object specifications into the Sharable Content Object Reference Model (SCORM), and is currently involved in defining an infrastructure that will support content repository search and retrieval operations, the CORDRA system.
While the prototype CORDRA registry will be an ADL Registry of SCORM-conforming content objects for deployment by the US government, CORDRA registries are not limited to including information about SCORM content.
What activities are planned for the CORDRA project?
The initial efforts of the project are to define and describe the necessary infrastructure. This will result in the production of specification-type documents that comprise the model.
Also underway is building the ADL Registry, a federated registry of metadata from a collection of content repositories.
Other CORDRA projects will extend and build upon the initial set of pilot projects. Down the road, CORDRA will expand to include the next level of federation -- a super-level "federated registry of the registries".
Where will the CORDRA "system" reside?
While individual content repositories can exist anywhere, each federated registry and the federated registry of the registries will need to reside somewhere; the location of these entities is yet to be determined.
How do organizations decide if CORDRA is something they should become involved with?
Any group dealing with the problem of sharing structured collections of digital material may want to become involved in, or at least follow, the CORDRA project to see if it is useful to them. Initially, CORDRA is addressing the general problem of federated repositories from the perspective of e-learning, so the project should be especially relevant to those in the e-learning field. While the high level technical architecture of the CORDRA model is already mapped out, no one can predict what types of organizational and social entities will ultimately develop in the global CORDRA community.
When can others become participants in CORDRA activities?
To become involved, interested parties are encouraged to attend meetings and keep up with documents and technical notes as they are posted here. Recommended background reading on this site includes:
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CORDRA: Technical Introduction and Overview
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PDF
(20040502)
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What's "CORDRA"™, an informational list of terms that helps
clarify the confusion associated with CORDRA;
- Other technical documents.
What is the status of the CORDRA model and CORDRA project activities?
Key project plans and goals for 2005 include:
- Carry out pilot testing of the ADL Registry
- Put the ADL Registry into limited production
- Hold various events to inform and engage interested organizations (see Events)
- Produce and post additional documentation on the CORDRA site