Understanding EAD: Structuring Archival Metadata for the Digital Age
Encoded Archival Description, or EAD, is one of the key tools that archivists use to represent the contents and structure of a finding aid in a digital environment. While a traditional finding aid might be a PDF or printed document, EAD allows this same information to be machine-readable, structured, and ready for integration into databases and discovery tools.
What is EAD?
According to the Society of American Archivists (SAA), EAD is a standardized XML (eXtensible Markup Language) format for encoding archival finding aids. It doesn’t dictate the content of the finding aid (that’s the job of DACS—Describing Archives: A Content Standard) but provides a consistent structure that helps software and search engines interpret and display the information.
What is XML?
XML is a markup language used to encode documents in a format that is both human-readable and machine-readable. Unlike HTML, which will still display a page even if coded incorrectly, XML will not function at all if the markup is invalid. This makes XML a precise tool for archivists who need dependable structure and consistency.
Why EAD Matters
EAD allows us to:
Present archival metadata in a structured, portable way
Enable better search and discovery in online systems
Link archival descriptions to digitized materials
A Brief History of EAD
EAD was first developed in the 1990s and has gone through several iterations:
EAD 2002: Widely adopted and still in use in many repositories
EAD3: Released in 2015 with improvements for internationalization, accessibility, and machine-actionability
EAD was developed alongside DACS, which defines what information should go into a finding aid. EAD provides the structure for that content, using XML tags to define elements like titles, dates, names, and subjects.
How EAD Changes
The SAA maintains the EAD standard through its Technical Subcommittee on Encoded Archival Description. Updates and revisions are posted on GitHub, which allows for community input and clear tracking of changes. EAD evolves to meet the needs of modern archives, with improvements often targeting interoperability and clarity.
Do You Need to Use EAD?
Not every repository uses EAD, and that's okay. Before jumping in, ask:
Where will your finding aids be hosted?
Will your content management system accept EAD?
Do you have staff or volunteers familiar with XML?
Repositories participating in statewide or national consortia, like the National Finding Aid Network (NAFAN), may require or recommend EAD for consistency across systems.
Anatomy of an EAD Document
An EAD file is made up of tags that group information by function:
<eadheader>: Contains metadata about the finding aid itself (title, publication date, language, etc.)<archdesc>: The main archival description, which includes everything from access restrictions to scope and content notes<did>: Descriptive Identification, containing basic elements like title, creator, and date<c>: Container elements, which describe the contents of boxes, folders, or digital items
Common Elements Within EAD
Dates: Use the
<unitdate>tag to define date ranges or single datesNames: Use
<persname>,<corpname>, or<famname>to describe people, organizations, or familiesSubjects: Described using
<subject>, often with controlled vocabularies
Using standardized vocabularies such as the Library of Congress Subject Headings (LCSH) or the Getty Art & Architecture Thesaurus (AAT) enhances interoperability and search accuracy.
Key Tools and Resources
EAD or Encoded Archival Description
EADiva: A detailed resource by Ruth Kitchin Tillman
Library of Congress EAD site
Whether you're just beginning to explore structured archival description or looking to update your existing finding aids, EAD is a powerful tool for ensuring your collections remain discoverable and usable in an increasingly digital research landscape.
