Understanding RDA: The Content Standard
Resource Description and Access (RDA) is the successor to the Anglo-American Cataloguing Rules, Second Edition (AACR2), developed specifically for describing resources in the digital age. Instead of dictating a specific display format, RDA provides instructions and guidelines for formulating descriptive metadata for library and cultural heritage materials. Its focus is on the intellectual and artistic content of a resource, its carriers, and the relationships it holds with other works, expressions, manifestations, and items (WEMI). The core purpose is to help users find, identify, select, and obtain the resources they need.
The Role of RDA in Descriptive Cataloging
RDA guides catalogers in recording a resource's attributes and its creators, which is a fundamental shift from the display-centric approach of older standards. This content-focused approach allows for greater flexibility and adaptability in how data is presented in various systems, from traditional online public access catalogs (OPACs) to linked data environments. RDA's strength lies in its ability to manage the recording of data separately from its presentation, a key feature for ensuring longevity and interoperability in an ever-evolving technological landscape. It provides instructions on what information to record and how, ensuring consistency and rich descriptive metadata.
What is a Data Value Standard?
In contrast to RDA, a data value standard provides the specific, controlled terms used to populate metadata fields. These standards—often called controlled vocabularies, thesauri, or authority files—ensure uniformity and consistency in data entry, which in turn enhances search and retrieval. Without standardized values, catalog searches would be far less effective. For instance, a search for a subject would fail if one cataloger used "computers" and another used "electronic data processing." Data value standards like the Library of Congress Subject Headings (LCSH) or the Getty Thesaurus of Geographic Names (TGN) prescribe the exact terms to use.
Comparison: RDA (Content Standard) vs. Data Value Standards
| Feature | RDA (Content Standard) | Data Value Standard |
|---|---|---|
| Primary Function | Provides guidelines for what data to describe and how to record it based on a resource's attributes and relationships. | Provides a controlled list of pre-authorized terms to use when describing data. |
| Example | Instructs a cataloger to describe the "creator" of a work and the relationship type, such as "author" or "artist". | Supplies the canonical, authorized name of a person or corporate body, such as "Tolkien, J. R. R." from the LC Name Authority File. |
| Focus | Defines the nature and structure of the metadata itself, focusing on a resource's core intellectual or artistic content. | Regulates the specific terminology used to fill a metadata field, ensuring uniformity and precision. |
| Scope | Encompasses descriptive cataloging rules for a wide array of resources, including print, digital, and multi-media formats. | Typically focused on specific domains, such as subject headings, place names, or artist names. |
| Relationship with other standards | Works in conjunction with data value standards and encoding schemas like MARC 21 to produce a complete bibliographic record. | Is used to populate fields created and governed by content standards like RDA. |
Why the Distinction Matters
The separation between RDA as a content standard and data value standards is critical for the long-term health of bibliographic data. It allows for flexibility in the evolving digital environment. By focusing on the "what to describe" (RDA) and not the "what to say" (data value standards) in a resource, cataloging guidelines can remain stable even as terminology and controlled vocabularies evolve. This modularity also enhances linked data capabilities, where relationships between entities are defined by a content standard like RDA, but the entities themselves are controlled via authority files.
Conclusion: RDA is a Content Standard
In summary, RDA is not a data value standard, but rather a content standard that provides the rules for describing resources. It is used in conjunction with data value standards like authority files and thesauri to create comprehensive and well-structured metadata. This crucial distinction allows RDA to provide a flexible and robust framework for descriptive cataloging that can adapt to new formats and emerging digital environments while still ensuring consistent and high-quality data. By defining the rules for what data to record, RDA facilitates the creation of discoverable and interoperable resource descriptions that serve both traditional library users and the demands of the modern web.
RDA and Other Standards: A Closer Look
- Integration with Encoding Schemas: RDA was designed to be compatible with various encoding schemas, such as MARC 21, Dublin Core, and ONIX. This compatibility allows RDA-compliant data to be used in a range of digital environments, ensuring library bibliographic records can be integrated with other metadata communities.
- Basis in Conceptual Models: RDA is based on the conceptual models developed by the International Federation of Library Associations (IFLA), such as the Functional Requirements for Bibliographic Records (FRBR) and Functional Requirements for Authority Data (FRAD). These models focus on user tasks and help structure the metadata in a more logical, user-friendly way.
- Enriching Metadata: By encouraging the description of relationships between related resources, such as different editions or formats of a work, RDA enables systems to group records together for a more meaningful display. This linked data approach significantly enhances resource discovery and the overall user experience.
- Beyond Libraries: While its primary user base is librarians, RDA is also applicable in other cultural heritage institutions, including archives and museums. Its extensible framework provides a consistent way to describe a wide variety of materials.
- The RDA Toolkit: The instructions for RDA are available via a web-based product known as the RDA Toolkit, which allows catalogers to navigate and implement the standards efficiently. The Toolkit also includes mappings to different schemas and policies from major libraries.
Conclusion: RDA is a Content Standard
In summary, RDA is not a data value standard, but rather a content standard that provides the rules for describing resources. It is used in conjunction with data value standards like authority files and thesauri to create comprehensive and well-structured metadata. This crucial distinction allows RDA to provide a flexible and robust framework for descriptive cataloging that can adapt to new formats and emerging digital environments while still ensuring consistent and high-quality data. By defining the rules for what data to record, RDA facilitates the creation of discoverable and interoperable resource descriptions that serve both traditional library users and the demands of the modern web.
Frequently Asked Questions
What is the difference between a content standard and a data value standard?
A content standard, such as RDA, provides the rules for describing what information to record about a resource. A data value standard, like LCSH, is a controlled list of terms and names used to populate the fields defined by the content standard.
Is RDA a replacement for MARC?
No, RDA is not a replacement for MARC. MARC (Machine-Readable Cataloging) is a data encoding format, or schema, used to store and exchange bibliographic data. RDA provides the content and instructions for populating the MARC fields, not the format itself.
How does RDA handle digital resources differently from AACR2?
RDA was designed specifically for the digital environment, providing clear guidelines for describing digital objects, e-books, and multimedia content. It separates the concepts of content type, media type, and carrier type, unlike AACR2 which used the less flexible General Material Designation (GMD).
What are FRBR and FRAD, and how are they related to RDA?
FRBR (Functional Requirements for Bibliographic Records) and FRAD (Functional Requirements for Authority Data) are conceptual data models developed by IFLA. RDA is based on these models, which focus on user tasks and define the relationships between entities like work, expression, manifestation, and item.
Does RDA dictate how catalog records must be displayed?
No, RDA is explicitly not a display standard. It provides guidelines for recording data independently of how it will be presented to the end-user. This separation allows for greater flexibility in how data is shown in various library systems.
How does RDA help improve resource discovery?
RDA enhances resource discovery by providing a consistent framework for describing resources and their relationships. It enables systems to better organize and link related records, which helps users more easily find, identify, select, and obtain the information they need.
What is the RDA Toolkit?
The RDA Toolkit is the official, online platform for accessing the RDA instructions and related cataloging resources. It provides a web-based, interactive tool that includes the text of RDA, mappings to different schemas, and policy statements from major libraries.
