DOI: Basics and Resources

A Digital Object Identifier (DOI) is a unique and persistent identifier which provides a link to an object on the Internet via a registration and indexing service.

Why learn about DOIs?

DOIDOIs are often used in citations and discovery services to provide permanent links to online articles, ebooks, images, reports, and other types of online objects.  Publishers now regularly assign a DOI to each journal article or ebook (or ebook chapter) they publish.  Many times, when a direct link or OpenURL lookup fails, an item still can be located using its published DOI.  Even if an object changes location on the Internet, its DOI will remain the same (and point to the new location).

The Basics

The Digital Object Identifier system is an ISO standard (ISO 26324) officially maintained by the International DOI Foundation (IDF).  The IDF provides the infrastructure to support DOIs by governing independent DOI Registration Agencies.  It was created in 1997 with DOI becoming a standard in 2012.

Note that according to the IDF, a DOI is a “digital identifier of an object” rather than an “identifier of a digital object”.

DOI Format

Each Digital Object Identifier has a unique alphanumeric string made up two parts:

{prefix}/{local name}

The prefix is a numeric string beginning with 10. and followed by several more numbers, usually four (ex. 10.1103).  The prefix is assigned by a Registration Agency to a publisher, institution, organization, or other types of Registrant.

The local name (suffix) follows the forward slash and is a unique alphanumeric string (for that prefix).  The local name for an object is chosen by the Registrant using whatever naming scheme they want
(ex. PhysRevLett.116.061102).

If you’re curious about why the DOI has its particular structure, see the Handle.Net Registry Technical Manual.

DOI URL

A DOI handle can be converted into a useful URL by adding it as a path after the domain https://doi.org.

So, for the previous prefix and local name (suffix) examples above, the full linkable URL would be:

https://doi.org/10.1103/PhysRevLett.116.061102

Note that older DOI URLs use the http://dx.doi.org format which was deprecated in 2016 (but is still supported).

DOI Uses

As stated, the Digital Object Identifier often points to digital content such as journal articles and ebooks (or individual chapters or even data).  Because DOIs provide a permanent link to these scholarly works, they are now frequently included—and sometimes required by journal publishers—in citations.  Of course, the various style guides have rules on how to format them in citations.  Here is an example of an APA citation with a DOI:

APA citation with a DOIAll of the style guides offer help for adding DOIs to citations.  Major ones include:

Publisher sites and databases often include DOIs in the online article or ebook itself.  This makes it easy to cite or to make a persistent link in a reading list.  For example, if an article has a DOI, Elsevier displays it as a link after the title and author(s).

DOI in an Elsevier articleDigital Object Identifiers are part of the metadata indexed in library discovery services.  EBSCO Discovery Service, Primo, Sierra, Summon, and WorldCat Discovery all display a DOI field on search results or on item detail screens (if available).  Sometimes they are links.  Including the DOI is useful when the search result link is broken as it provides a secondary method for locating the resource.  For example, Summon displays the item’s DOI as a link when you expand the “Preview” section.

Summon result with DOIDOI Registration

For many years librarians and researchers have been using Digital Object Identifiers.  More and more librarians are becoming the creators and maintainers of DOIs as yet another type of metadata to enhance discovery and access.  As we have seen, DOI links point to a URL that serves as a central index and redirection service.  DOI URLs are translated into the actual URL of the target object.  So how does this index get built?

The central DOI index is maintained by several DOI Registration Agencies.  The most important of these is Crossref.  Publishers and other institutions become members and pay to create DOIs for their items.  With the rise of university publishing and institutional repositories, more universities are enhancing their scholarly output with DOIs to aid in their discovery and sharing.  Increasingly, librarians are assisting university faculty with creating DOIs as part of the publishing process.  Cataloging and scholarly communications librarians are frequently tasked with creating and managing the DOIs for these repositories.

Resources

Here are official resources to learn about DOIs:

  • DOI.org – Website of the International DOI Foundation (IDF).
  • DOI Handbook – Official source of information about the DOI system.
  • Driven by DOI – Watch videos and download brochures.

Library-related DOI registration agencies:

  • Crossref – Popular DOI agency for scholarly publishing.
  • DataCite – “[L]eading global provider of DOIs for research data.”
  • mEDRA – Multilingual European Registration Agency.

Useful DOI tools:

  • DOI Citation Formatter – Crosscite will format an entered DOI in one of hundreds of citation styles.
  • DOI Resolver – Google Chrome extension to create links and citations from a DOI.
  • Custom DOI resolver – Firefox extension to turn a non-linked DOI into a URL.

Library Technology at the ALA 2017 Annual Conference

ALA 2017 Annual Conference

The ALA 2017 Annual Conference is just one week away.  The conference covers a myriad of library topics and sorting through the program sessions to find the ones focused on library technology takes effort.  Let us do the work for you.

Here is our list of programs related to library technology.  You’ll find interest groups and sessions on data and metadata, makerspaces, UX, Linked Data, ILS and LMS, websites, mobile apps, emerging technologies, and more.  Committee meetings were not included.

For official descriptions, speakers, and final schedule, please check the conference Full Schedule page.
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OAI-PMH: Basics and Resources

Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) is a set of specifications for making structured open repository metadata accessible to other service providers issuing requests.

Why learn about OAI-PMH?

Taking advantage of repositories (data providers) and services (service providers) that offer metadata using OAI-PMH will allow your resources better visibility and access.  For example, many discovery services (the “harvester”) use OAI-PMH metadata for indexing open access institutional repository articles.

The Basics

Open Archives InitiativeOpen Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) specifies how metadata is structured and presented for ingestion by external services, usually on the Internet.  OAI-PMH metadata is encoded in extensible markup language (XML) format.  OAI-PMH records are harvested using HTTP requests.

OAI-PMH is a project of the Open Archives Initiative.

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Basics and Resources Series 2016

Last year we created a Basics and Resources series to introduce some common library technology topics.  As you can guess from the name, in each article we introduced the basic concepts and listed resources where you could learn more.  Based on feedback, these articles proved very popular and we will be posting more in the coming year.

The Basics and Resources articles from 2016 were:

Linked Data

Linked Data mugLinked Data is a set of practices which involves the publishing, sharing, and connecting of related data across the Web in a structured format, preferably using an open access license.

Read Linked Data: Basics and Resources.

BIBFRAME

BIBFRAMEBIBFRAME is a bibliographic framework for the description of physical and online objects to make them accessible on the Web by using a standard Linked Data model. It is a replacement for MARC.

Read BIBFRAME: Basics and Resources.

Altmetrics

Altmetric ScoreAltmetrics are “alternative metrics” to measure the influence and reach of scholarly output on the Web through peer-review counts, influential news sites and blog posts, citation manager bookmarks such as Mendeley, Wikipedia citations, and social media mentions on sites such as Twitter and Facebook.

Read Altmetrics: Basics and Resources.

API

API GraphicAPI stands for Application Programming Interface which allows external applications to access software or Web services data, in the latter case by using HTTP request messages, for recombination (mashup) or custom presentation by the external application.

Read API: Basics and Resources.

We will keep a current list on the Basics and Resources Series page.

API: Basics and Resources

API stands for Application Programming Interface which allows external applications to access software or Web services data, in the latter case by using HTTP request messages, for recombination (mashup) or custom presentation by the external application.

Why use APIs?

Application programming interfaces essentially allow programs and online services to talk to each other.  APIs provide a set of definitions and protocols for services to request and exchange data.  Many library vendors provide public and key-based APIs to their services in order to allow customers to pull bibliographic and other data into local systems and websites.

The Basics

For our purposes, we’ll only look at Web APIs.

Web services and applications exchange data through APIs using a request and response system.  The exchange uses HTTP and HTTPS (secure HTTP) like regular Web requests, however the data isn’t formatted for people to read but rather for other services.  The data format is usually expressed in JavaScript Object Notation (JSON) or Extensible Markup Language (XML).

API Graphic

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