What is a DOI Number in Citation?
Definition of a DOI Number
A DOI (Digital Object Identifier) is a unique, permanent string of numbers, letters, and symbols used to identify a specific scholarly work. Unlike a URL, which points to a website location that may change, a DOI provides a persistent link to the content itself, ensuring researchers can always locate the source.
DOI vs. URL: Key Differences
| Feature | DOI (Digital Object Identifier) | URL (Uniform Resource Locator) |
|---|---|---|
| Permanence | Permanent and unchanging | Can break or change (link rot) |
| Purpose | Identifies the content itself | Identifies the web location |
| Format | Starts with 10. followed by a prefix | Starts with http:// or https:// |
| Stability | High; managed by central registries | Low; depends on the site owner |
| Academic Preference | Highly preferred for citations | Used only if a DOI is unavailable |
| Uniqueness | One unique code per document | Multiple URLs can point to one doc |
How a DOI Works
A DOI is assigned by a registration agency like Crossref to academic journals, books, and datasets. It consists of two parts: a prefix and a suffix. The prefix usually identifies the publisher, while the suffix identifies the specific work. Because the DOI is registered in a central database, if a publisher moves their content to a new website, they simply update the metadata. This means the DOI link remains functional while a standard URL would lead to a 404 error page.
DOI Citation Examples
Below is an example of how a DOI appears in a formal APA citation compared to a source where only a URL is available. **With a DOI (Preferred):** Author, A. A. (2023). Title of the article. *Journal Name*, 12(3), 45-60. https://doi.org/10.1016/j.jbusres.2023.01.001 **Without a DOI (URL only):** Author, B. B. (2023). Title of the article. *Journal Name*, 15(1), 10-20. https://www.journalwebsite.com/article-path Note that the DOI is now typically formatted as a full URL link (https://doi.org/...) to make it clickable for readers.
Where to Find the DOI
You can usually find the DOI in the following locations:
1. The first page of a PDF article, often in the header or footer.
2. The landing page of the article on the publisher's website.
3. The database record (like EBSCOhost or ProQuest) under the 'Abstract' or 'Details' section.
4. If it is not listed, you can search for the article title on Crossref.org to see if a DOI has been assigned.
Pro Tip for Researchers
Always prioritize the DOI over the URL in your reference list. If your source has both, include only the DOI. It makes your bibliography look more professional and ensures your professor can find your sources even months after you submit your essay.
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