Metadata for You & Me - A Look at Sharing: The Current Sharing Environment

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1. Questions to ask yourself

As you read through the content in this module, consider the following questions.

2. Why share?

But perhaps we ought to back up and ask the question 'why share?' How does sharing our metadata benefit our users? How does sharing our metadata benefit us?

We believe that sharing has many benefits for users:

Sharing metadata also has benefits for those organizations willing to share:

Are there other benefits for users or our institutions to sharing?

3. An abridged history of metadata sharing

Some milestones in the history of sharing metadata:

As this timeline shows, sharing information about our collections is far from a new idea. In fact, sharing information about what we hold in our collections has been an important activity since the founding of many cultural heritage organizations. Today we face new challenges about the methods we use to share, but they are not unlike those faced by our predecessors.

With the advent of printing technologies, many museums and libraries began publication of bibliographies and catalogues of their collections in the seventeenth-century. These catalogues often became important reference works for other repositories that allowed scholars to learn about collections located elsewhere.

For the library community, methods of sharing catalog records also have a more recent lineage. In 1877 Melvil Dewey standardized dimensions for catalog cards and established a service bureau to supply libraries with catalog cases (the hardware) and cards (software). In 1901 the Library of Congress was able to take advantage of this standardization by widely distributing catalog cards to other libraries based on its acquisitions.

With the advent of automation in the late 1960s and 70s, sharing of computer coded records was now possible. The Library of Congress was again at the forefront of this development when it received funding to develop the MAchine Readable Catalog (MARC) record format between 1966 and 1967. With approval from national and international library community the MARC format laid the foundations for collaborative cataloging efforts and distribution of MARC records on tape in 1969. By the early 1970s statewide collaboratives such as NELINET and the Ohio Computer Library Consortium (later the Online Computer Library Center - OCLC) developed online networks for shared cataloging and the production of catalog cards and eventually online access catalogs for public use.

Similar efforts were underway in the art museum community with the formation of the Museum Computer Network in 1967 and the application of computers to archeological and natural science collections. While these efforts did not result in a single large-scale catalog of museum collections, the profession had begun to explore the possibilities of creating shared networks. Natural history museums, in particular, have participated in growing repositories of biodiversity information.

With the growth of information resources on the Internet, OCLC and other organizations created the Dublin Core in 1995 as a lightweight format for describing online content. Other communities extended the concept of core metadata elements by creating profiles that were appropriate for their resources. Examples include the VRACore, CDWA Lite and the Darwin Core, as well as other Dublin Core Application Profile communities.

As users increasingly relied on mainstream search engines to find content on the Web, many content owners were concerned that their content was not being found. The Open Archives Initiative - Protocol for Metadata Harvesting (OAI-PMH) was released in 2001 in order to expose the "deep web" and provide a mechanism for interoperability and dissemination of content.

Sharing information about resources relies not only on data format standards, but also on content standards. The Joint Steering Committee for the Ango-American Cataloging Rules (AACR) has created a timeline outlining the development of bibliographic cataloging rules. Like data standards, other communities frequently adopted bibliographic rules for description for their own community, examples include Archives, Personal Papers, and Manuscripts (APPM), Describing Archives: A Content Standard (DACS), and Cataloging Cultural Objects (CCO).

Next we will cover two different ways that metadata can be shared: federated search and data aggregation. There are other ways that metadata can be shared (via RSS feeds for example), but we will cover more of these at the end of the course.

4. Federated Searching

In federated search methods, a users query is broadcast to a number of different databases that are registered with the system. Each individual database sends results back to the query service, which collates the results for the user. Z39.50, SRU and other metasearch technologies rely on federation for their searches.

Pros:

Cons:

Federated Searching

5. Data Aggregation

Aggregation services routinely collect information from identified resources and create a new aggregated data source for users to search. Because aggregations provide a surrogate set of data for users, it is not dependent on multiple remote services and aggregation managers can provide value-added enhancements based on the entire set of data collected. The Open Archives Initiative-Protocol for Metadata Harvesting (OAI-PMH) and large search engines such as Google Scholar (and Google) rely on aggregated search.

Pros:

Cons:

Aggregation

6. Safe Assumptions about Sharing Metadata

The metadata sharing landscape is constantly changing. However, given the current environment, there are a few assumptions it is safe to make, to guide you in preparing your metadata for sharing.

Are there other assumptions about the current environment of sharing records that should be listed here?

Next module: A Look at Sharing: Aggregators