In general, repositories are storehouses for significant digital assets. These assets might include documents, images, audio and video files, and data sets. The inner workings of a repository help organize and preserve materials, making it simpler to keep track of what has been deposited and easier for others to find and to use the material.

One of the sideline projects for UAiR personnel is the creation and upkeep of "What is a Respository?" in UAiR's Knowledge Base.

Definitions vary with each repository. Some repositories are dedicated to specific collections or collection types, such as historical documents or engineering specifications or legal documents. Some repositories are designed for the important output of a single department. Some repositories, such as UAiR, are designed to store the deposits from the University, our collaborators, and other significant contributors. (See also What is a digital asset? below.)

OAI (sometimes written OAI-PMH) is an acronym for the Open Archives Initiative. OAI has established methods and practices for repositories in an effort to keep all intellectual digital objects openly accessible for anyone to study, review, and enjoy. It is common to be told that OAI refers to “Open-Access Initiative”. Digital Commons personnel are developing many OAI tools, including techniques for harvesting objects and metadata and rendering either via the Web.

PID is a universal concept for repositories, including the Digital Commons. PID stands for Persistent Identifier. A PID is assigned to each object deposited into UAiR and repositories around the world. A PID is unique to each object and is used to identify objects within repositories for harvesting and use in Web applications and pages.

In the language of repositories, an object is the generic term for any digitized file or resource. A digital asset is an object. The terms (digital asset, object, and digital object) are used interchangeably.
Any object accepted for deposit and included in UAiR or any other repository, whether restricted or unrestricted, is called an asset or digital asset.

OAI standards include a uniform URI structure that uses persistent identifiers (PID) to access objects and abstracts in repositories. URIs for restricted (unexposed) objects and abstracts are not published. Information about the URI structure and OAI harvesting specifications, follow the OAI link on any Digital Commons Web page.

Repositories are designed for long-term preservation of digital objects. Important assets can be stored and harvested months, years, even decades in the future for study, analysis, and enjoyment. From a repository, researchers, educators, and aficionados can “harvest” information to further knowledge and personal development. Unless specific restrictions are assigned to digital assets, repositories are generally open and, through the use of OAI-standard methods and practices, deposits can easily be shared.
In addition to exposing the assets stored in UAiR, digital assets from repositories around the world can be linked, referenced, joined, and used to create collections, subcollections, classroom materials, digital exhibits, and research projects. As the Digital Commons matures, federation with other repositories will become rather simple, and the research possibilities are virtually endless.

Harvesting is when a repository administrator incorporates the metadata from another institution's repository and incorporates the metadata into their own. For example, suppose a repository at the University of Oklahoma includes a digitized collection of Will Rogers' letters, and the University of Arizona has a digitized collection of images from Will Rogers' appearances. The University of Oklahoma can harvest the metadata from the Digital Commons at the University of Arizona and present the images from UA along with the letters they already hold. The University of Oklahoma harvests only the metadata. When a researcher or student clicks a link for the images, the servers at the University of Arizona deliver the image(s). Harvesting is an incredibly powerful tool in repositories. With sufficient disk space, there is no limit to the number of repositories used to create a unique collection nor the number of exposed objects one might use from around the world.

A repository administrator is someone who has been trained in the practices, terminology, requirements, technical issues, and metadata formats of UAiR. A repository administrator can be anyone who works with UAiR. Most repository administrators are subject-matter experts. UAiR includes links to the list of repository administrators and an application for those who would like to become a repository administrator. The repository administrator is the point of contact for anyone who wants to begin the process of depositing assets in UAiR.

OAI standards include a uniform URI structure that uses persistent identifiers (PID) to access objects and abstracts in repositories. URIs for restricted (unexposed) objects and abstracts are not published.

A federation is a consortium of repositories. Federations are usually formed regionally by institutions that independently support repositories and hold digital assets with strong common themes or subject interests. For example, UAiR might federate with Arizona State University and Northern Arizona University to present in concert any and all assets in each of the repositories as though they were a single repository. Other federations can be created for large-scale harvesting efforts based on collections or subject matter. Anyone interested in federating with UAiR should contact us.

In repository “speak”, the term expose means simply to make public. If an object is unexposed, it is hidden from the public.

The Digital Commons is administered by the University of Arizona Libraries. For more information, contact the Digital Commons.

The history of UAiR is included in the FAQ About UAiR.

With any large-scale repository such as UAiR, there are thousands of things to do. Volunteer scholarly work is always available. Suggestions for content and educational materials are always welcome. Donations and grant funding are always greatly appreciated. contact the Digital Commons.