Metadata is communication; it can tell a story about research and paint a picture for others to respond to and learn from, across the world and throughout the forthcoming generations. Metadata can feel technical with words like ‘infrastructure’ and ‘schema’, and sometimes, like tech in general, it comes with hyperbole. But metadata really is part art (storytelling and pictures) and part science (structured models and standards) with both aspects being equally important, and requiring people as well as systems. That necessary combination of human and machine involvement also makes metadata challenging.
Once a year we release all metadata records for content registered with Crossref in a public data file. This year’s version, containing nearly 180 million records, is now available. It includes metadata associated with all Crossref-registered DOIs in JSON-lines format.
Crossref Ambassadors act as local points of contact, meeting editors, librarians, researchers, and institutions to help them navigate Crossref services and understand how strong metadata supports visibility, integrity, and trust in research. They explain how to participate in our rich network of connections between works, people, and institutions, in ways that make sense in their own contexts. And last year, being our 25th anniversary, Ambassadors also massively contributed to our celebrations!
We have renewed our partnership with DOAJ to focus on a new set of objectives that reflect both organisations’ commitment to improving sustainable and equitable services and infrastructure. This renewed collaboration focuses on improving the quality of scholarly metadata while expanding support for journals in low- and middle income- countries.
We have worked together since 2021, primarily to encourage the dissemination and use of scholarly research using online technologies, and regional and international networks, partners and communities. This partnership has helped to build local institutional capacity and sustainability within the global scholarly communication ecosystem. A continued partnership also reflects that we have a shared community; currently almost 90% of DOAJ journals are represented in Crossref.
A DOI may refer to a journal or book (a title-level DOI), or to a specific article or chapter.
Journals and DOIs
Like a set of nesting dolls, a journal may be made up of volumes, each containing a number of issues, each containing a number of articles. You can assign a DOI at each level, for example:
journal-level-DOI (sometimes called the title-level-DOI) 10.5555/QYPF2031. Like an ISSN, it refers to the whole journal
volume-level-DOI 10.5555/FFFU4804
issue-level-DOI 10.5555/QKLE5634
article-level-DOI 10.5555/CNBT7653
The role of the journal-level-DOI, volume-level-DOI, and issue-level-DOI is to link persistently to a point in the journal structure. These DOIs do not have any associated content, and it does not cost anything to register these DOIs.
However, article-level-DOIs do have associated content, and therefore a fee applies to register these DOIs.
Books and DOIs
Like a set of nesting dolls, a book may be made up of chapters. Again, you can assign a DOI at each level, for example:
book-level-DOI (sometimes called the title-level-DOI) 10.5555/ZAAR1365. Just like an ISBN, it refers to the whole book.
chapter-level-DOI 10.5555/TFWD2627
Both book-level-DOIs and chapter-level-DOIs have associated content, and therefore a fee applies to register these DOIs.
