Metadata to Support Next-Generation Library Resource Discovery: Lessons from the eXtensible Catalog, Phase 1

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The eXtensible Catalog (XC) Project at the University of Rochester will design and develop a set of open-source applications to provide libraries with an alternative way to reveal their collections to library users. The goals and functional requirements developed for XC reveal generalizable needs for metadata to support a next-generation discovery system. The strategies that the XC Project Team and XC Partner Institutions will use to address these issues can contribute to an agenda for attention and action within the library community to ensure that library metadata will continue to support online resource discovery in the future.

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Library metadata, whether in the form of MARC 21 catalog records or in a variety of newer metadata schemas, has served its purpose for library users by facilitating their discovery of library resources within online library catalogs (OPACS), digital libraries, and institutional repositories. However, libraries now face the challenge of making this wealth of legacy catalog data function adequately within next-generation Web discovery environments. Approaching this challenge will require:

* an understanding of the metadata itself and a com mitment to deriving as much value from it as pos sible;

* a vision for the capabilities of future technology;

* an understanding of the needs of current (and, where possible, future) library users; and

* a commitment to ensuring that lessons learned in this area inform the development of both future library systems and future metadata standards.

The University of Rochester's eXtensible Catalog (XC) Project will bring these various perspectives together to design and develop a set of open-source, collaboratively built next-generation discovery tools for libraries. The XC Project Team seeks to make the best possible use of legacy library metadata, while also informing the future development of discovery metadata for libraries. During Phase 1 of the XC Project (2006-2007), the XC Project Team created a plan for developing XC and defined the goals and initial functional requirements for the system. This paper outlines the major metadata related issues that the XC Project Team and XC Partner Institutions will need to address to build the XC system during Phase 2. It also describes how the XC Team and XC Partners will address these issues, and concludes by presenting a number of issues for the broader library community to consider.

While this paper focuses on the work of a single library project, the goals and functional requirements developed for the XC Project reveal many generalizable needs for metadata to support a next-generation discovery system. (1) The metadata-related goals of the XC Project--to facilitate the use of MARC metadata outside an Integrated Library System (ILS), to combine MARC metadata with metadata from other sources in a single discovery environment, and to facilitate new functionality (e.g., faceted browsing, user tagging)--are very similar to the goals of other library projects and commercial vendor discovery software. The issues described in this paper thus transcend their connection to the XC Project and can be considered general needs for library discovery metadata in the near future.

In addition to informing the library community about the XC Project and encouraging comment on that work, the author hopes that identifying and describing metadata issues that are important for XC--and that are likely to be important for other projects as well--will encourage the library community to set these issues as high priorities for attention and action within the next few years.

* The eXtensible Catalog Project

The University of Rochester's vision for the eXtensible Catalog (XC) is to design and develop a set of open-source applications that provide libraries with an alternative way to reveal their collections to library users. XC will provide easy access to all resources (both digital and physical collections) and will enable library content to be revealed through other Web applications that libraries may already be using. XC will be released as open-source software, so it will be available for free download, and libraries will be able to adopt, customize, and extend the software to meet their local needs. The XC Project is a collaborative effort between partner institutions that will serve a variety of roles in its development.

Phase 1 of the XC Project, funded by the Andrew W. Mellon Foundation and carried out by the University of Rochester River Campus Libraries between April 2006 and June 2007, resulted in the creation of a project plan for the development of XC. During XC Phase 1, the XC Project Team recruited a number of other institutions that will serve as XC Partners and who have agreed to contribute resources toward building and implementing XC during Phase 2. XC Phase 2 (October 2007 through June 2009) is supported through additional funding from the Andrew W. Mellon Foundation, the University of Rochester, and XC Partners. During Phase 2, the XC Project Team, assisted by XC Partners, will deploy the XC software and make it available as open-source software. (2)

Through its various components, the XC system will provide a platform for local development and experimentation that will ultimately allow libraries to manage and reveal their metadata through a variety of Web applications such as Web sites, institutional repositories, and content management systems. A library may choose to create its own customized local interface to XC, or use XC's native user interface "as is." The native XC interface will include Web 2.0 functionality, such as tagging and faceted browsing of search results that will be informed by FRBR (Functional Requirements for Bibliographic Records) (3) and FRAD (Functional Requirements for Authority Data) (4) conceptual models. The XC software will handle multiple metadata schemas, such as MARC 21 (5) and Dublin Core, (6) and will be able to serve as a repository for both existing and future library metadata. In addition, XC will facilitate the creation and incorporation of user-created metadata, enabling such metadata to be enhanced, augmented, and redistributed in a variety of ways.

The XC Project Team has designed a modular architecture for XC, as shown in the simplified schematic in figure 1. XC will bring together metadata from a variety of sources (integrated library systems, digital repositories, etc.), apply services to that metadata, and display it in a usable way in the Web environments where users expect to find it. (7) XC's architecture will allow institutions that implement the software to take advantage of innovative models for shared metadata services, which will be described in this paper.

* XC Phase 1 activities

During the now-completed XC Phase 1, the XC Project Team focused on six areas of activity:

1. Survey and understand existing research on user practices.

2. Gauge library demand for the XC system.

3. Anticipate and prepare for the metadata requirements of the new system.

4. Learn about and build on related projects.

5. Experiment with and incorporate useful, freely available code.

6. Build a community of interest.

[FIGURE 1 OMITTED]

The XC Project Team carried out a variety of research activities to inform the overall goals and high-level functional requirements for XC. This research included a literature search and ongoing monitoring of discussion lists and blogs, to allow the team to keep up with the most current discussions taking place about next-generation library discovery systems and related technologies and projects. (8) The XC team also consulted regularly with prospective partners and other knowledgeable colleagues who are engaged in defining the concept of a next-generation library discovery system. In order to gauge library demand for the XC system, the team also conducted a survey of interested institutions. (9)

This paper reports the results of the third area of activity during XC Phase 1--anticipating and preparing for the metadata requirements of the new system--and looks ahead to plans to develop the XC software during Phase 2.

* XC goals and metadata functional requirements

The goals of the XC Project have significant implications for the metadata functionality of the system, with each goal suggesting specific high-level functional requirements for how the system can achieve that particular goal. The five goals are:

* Goal 1: Provide access to all library resources, digital and non-digital.

* Goal 2: Bring metadata about library resources into a more open Web environment.

* Goal 3: Provide an interface with new Web functionality such as Web 2.0 features and faceted browsing.

* Goal 4: Conduct user research to inform system development.

* Goal 5: Publish the XC code as open-source software.

An overview of each XC goal and its related high-level metadata requirements appears below. Each requirement is then discussed in more detail, with a plan for how the XC Project Team will address that requirement when developing the XC software.

* Goal 1: Provide access to all library resources, digital and non-digital

Working alongside a library's current Integrated Library System (ILS) and its other Web applications, XC will strive to bring together access to all library resources, thus eliminating the data silos that are now likely to exist between a library's OPAC and its various digital repositories and commercial databases. This goal suggests two fairly obvious metadata requirements (Requirements 1 and 2).

Requirement 1--The system must be capable of acquiring and managing metadata from multiple sources: ILSs, digital repositories, licensed databases, etc.

A typical library currently has metadata pertaining to its collections residing in a variety of separate online systems: MARC data in an ILS, metadata in various schemas in digital collections and repositories, citation data in commercial databases, and other content on library Web sites. A library that implements XC may want to populate the system with metadata from several online environments to simplify access to all types of resources. To achieve Goal 1, XC must be capable of acquiring and managing metadata from all of these sources. Each online environment and type of metadata present their own challenges.

Repurposing MARC data

Repurposing MARC metadata from an existing ILS will be one of the biggest metadata tasks for a next-generation discovery system such as XC. In planning XC, we have assumed that most libraries will keep their current ILS for the next few years or perhaps migrate to a newer commercial or open-source ILS. In either case, most …