Digital Object Identifier: Definition & Examples

Instructor: Mary Firestone
Find out what digital object identifiers (DOI) are and what their function is. Learn how to find DOI's for your articles, and where to place them on your References page. Read the lesson, and take a quiz to test your knowledge.

Digital Object Identifier

You might have seen the letters 'DOI' before, and wondered what they're all about. Digital object identifiers (DOI) serve a purpose when citing online articles, because they offer a permanent link to the source. Links to articles on websites are vulnerable to change, but the DOI will always connect to the right article.

How it Works

Publishers assign a unique alpha-numeric identification to each publication. All DOI's begin with the number 10. Here's an example below, which links to a peer-reviewed journal article about probiotics:


If you copy and paste this DOI into your search engine, it will open to the webpage where the article is published:

The advantage of the DOI system is that even if an article's current location changes or is deleted, the DOI will always link to the article no matter where it resides.

Finding the DOI

Peer-reviewed journals and books frequently have DOIs. If you go to an EBSCO or ProQuest database at your library and enter your topic in the search box, several articles will display. Click on the one you want, then scroll down past the abstract until you see the 'DOI' on the left. APA recommends using the DOI instead of a URL or web address, since it's a permanent link to the source.

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