Cross Collection Discovery

Cross Collection Discovery (CCD) provides a framework for Discover Yale Digital Content – a new collaborative service that allows a single faceted search and discovery of related content held by different campus units. This shared common infrastructure for harvesting metadata and delivering digital content will enable future lifecycle management and growth of assets within Yale's Digital Ecosystem.

CCD began in 2009 as a partnership among the Yale libraries, museums, and galleries, led by YDC2. The first release was in April 2011 with collections from five partners (Yale University Art Gallery, Yale Center for British Art, Yale Peabody Museum, Yale University Library, Office of Digital Dissemination) comprising 1.5 million records and 250,000 digital assets. The project will continue to grow to include new collections and features.

Project Description


The primary goals of the CCD project are to develop shared common infrastructure for metadata aggregation and dissemination and to provide open, integrated access to Yale collections.


The primary stakeholders are the YDC2 partners. The project serves two communities: users who want to discover and access content in the Yale Digital Commons; developers who want programmatic access to metadata to develop their own applications.

The Yale Center for British Art is using CCD to drive the collections search on its website. CCD enables users to search across YCBA collections managed in different databases from a single entry point.


The content discoverable from the Discover Yale Digital Content website comes from digitized collections of art, natural history, books, and maps, as well as photos, audio, and video documenting people, places, and events that form part of Yale's institutional identity and contribution to scholarship. The content discoverable from the site will grow as additional University departments make use of the service.


The Open Access Initiative Protocol for Metadata Harvesting (OAI-PMH) is used to harvest metadata from University departments and to provide programmatic access to the general public via an OAI data provider.

The metadata is indexed in Apache Solr. The metadata is accessible to the Yale community via Solr APIs and to users via Discover Yale Digital Content, a VuFind implementation customized for metadata from diverse communities.

Policy and Practice

CCD reinforces the value of shareable metadata that can be understood in a range of contexts. Project stakeholders have developed metadata mappings based on standards such as CDWA-Lite, Darwin Core, Dublin Core, and MARCXML and will assess ways in which the value of aggregation can be enhanced through the adoption of shared policy and practice.

CCD instantiates the University's open access policy. Stakeholders are currently serving their own assets. YDC2 will lead the development of a shared solution integrated with its digital asset management system that will greatly increase the number and format of publicly accessible digital assets in Discover YDC.

Get Involved

  • Please send feedback on Discover YDC to
  • Yale developers: For more information about how you can use Solr APIs to develop your own interfaces, please see References or contact
  • Other institutions: For more information about how you can harvest metadata from CCD, please see References or contact

Open Source Tools and Standards

ODAI Statistics: