The Crossref Nominating Committee is inviting expressions of interest to join the Board of Directors of Crossref for the term starting in 2021. The committee will gather responses from those interested and create the slate of candidates that our membership will vote on in an election in September. Expressions of interest will be due Friday, June 19, 2020.
The role of the board at Crossref is to provide strategic and financial oversight of the organization, as well as guidance to the Executive Director and the staff leadership team, with the key responsibilities being:
After 20 years in operation, and as our system matures from experimental to foundational infrastructure, it’s time to review our documentation.
Having a solid core of education materials about the why and the how of Crossref is essential in making participation possible, easy, and equitable.
As our system has evolved, our membership has grown and diversified, and so have our tools - both for depositing metadata with Crossref, and for retrieving and making use of it.
To help better support the discovery, sale and analysis of books, Jennifer Kemp from Crossref and Mike Taylor from Digital Science, present seven reasons why publishers should collect chapter-level metadata.
Book publishers should have been in the best possible position to take advantage of the movement of scholarly publishing to the internet. After all, they have behind them an extraordinary legacy of creating and distributing data about books: the metadata that supports discovery, sales and analysis.
Hello, I’m Paul Davis and I’ve been part of the Crossref support team since May 2017. In that time I’ve become more adept as a DOI detective, helping our members work out whodunnit when it comes to submission errors.
If you have ever received one of our error messages after you have submitted metadata to us, you may know that some are helpful and others are, well, difficult to decode. I’m here to help you to become your own DOI detective.
Structural metadata provides information about how research objects are organized, both within a research object (for example, a book composed of chapters, chapters composed of pages, and pages arranged in a particular order), and relationships between research objects (for example, a preprint, version of record, and a dataset). Learn more about version control, corrections, and retractions.
Within a nested structure, you may find DOIs at different levels. For example, a book chapter may have its own DOI, as may the book it belongs to. Likewise, a journal may have a DOI at the level of title, sometimes volume and issue, and article. A nested structure may also apply to conference proceedings.
Learn more about the three main types of metadata: descriptive (bibliographic), administrative, and structural.
Some journals have volumes and issues or parts. This structure is a legacy from print journals, where a collection of articles would be published together in an issue or part. An issue would be printed at intervals throughout the year, perhaps every month or every quarter. In the library, issues were arranged in order on the shelves. At the end of each year, they would be stitched together and given a hardback cover for protection, and this collection of issues was called a volume. The volume may have been named after the year (for example, 1997), or given a number (for example, 40).
In this way, each journal was made up of volumes, each containing a number of issues, and each containing a number of articles. Although many articles are now published electronically, rather than in print, the same structure is often used for online journals.
Books are divided into three categories, each requiring slightly different metadata:
Book: a book is single book (monograph) that is not part of a series or a set. The title-level metadata for the book is captured in <book_metadata>.
Book series: books that are part of an ongoing series and have an ISSN assigned should be deposited as a book series. Book metadata is captured in <book_series_metadata>, with series-specific details such as ISSN and series title captured in <series_metadata>. A series-level and volume-level title must be supplied for each book submitted as part of a series. A series-level ISBN and/or DOI may optionally be assigned. Examples of books in series:
Series: a sequence of books with certain characteristics in common that are formally identified together as a group. They may be released in successive parts once a year, or less often. For example, Loeb Classical Library or Oxford World’s Classics
Book set: book volumes that cannot stand alone as separate books must be deposited as a book set. A book set has a set-level title but does not require an ISSN. An ISBN and/or DOI may optionally be assigned at the set level. Example of a book set: Le Deuxième Sexe by Simone de Beauvoir, in two volumes: Les faits et les mythes and L’expérience vécue.
These connections may consist of citations, or refer to publications which do not always exist as a single content item (its parts may be produced, curated, and published by different organizations and separate activities). Making these connections creates linked data, which is useful because it establishes associations and context.
Crossref has also introduced other interlinking services that address specific types of relationships:
Crossmark supports the connection of updates which have a material effect on the original work, for example: updates, corrections, and retractions.
Funding data supports identifying the organization that financially supports the research behind a specific publication.
Components allow for the assignment of DOIs to the component parts of a publication (figures, tables, images) which may lead to their reuse.
These and other Crossref services create relationships between content items; however, they share two characteristics that restrict their ability to define relationships:
Both items involved in a relationship must be identified by Crossref-assigned DOIs.
The types of relationships are dictated by the mission of the specific Crossref service.
The following modifications and new services developed in response to these two limitations:
Allow non-Crossref DOIs to be deposited in an item’s (article/chapter/paper) list of citations.
Support the creation of general typed relationships between items with a Crossref DOI, and other content items with a variety of identifiers.
We maintain an expansive set of relationship types to support the various content items that a research object, like a journal article, might link to. For data and software, we ask you to provide the following information:
identifier of the dataset/software
identifier type: DOI, Accession, PURL, ARK, URI, Other (additional identifier types are also accepted beyond those used for data or software, including ARXIV, ECLI, Handle, ISSN, ISBN, PMID, PMCID, and UUID)
relationship type: isSupplementedBy or references (use the former if it was generated as part of the research results)
description of dataset or software
Both Crossref and DataCite use this kind of linking. Data repositories which register their content with DataCite follow the same process and apply the same metadata tags. This means that we achieve direct data interoperability with links in the reverse direction (data and software repositories to journal articles).
The possible relationship types between content items can be as varied as the items themselves. We use a controlled vocabulary to define these relationships, in order to construct an orderly mapped network of content.
This is achieved by (i) an implicit approach where the relation type is a function of a specific service and is declared in the structure of the deposited XML, and (ii) in an explicit approach where the relation type is selected as a value within the deposited metadata.
Reference linking and Cited-by: implicitly creates cites and isCitedBy relationships between a content item and the items in its bibliography
Crossmark: explicit creation of update relations between an item and other items that materially affect it (for example, a retraction)
Funding data: implicit creation of isFundedBy and hasAward relationships between an item and the funding source that supported the underlying research
Linked clinical trials: implicit creation of a belongsTo relationship between and item and a registered clinical trial
Components: implicit creation of a isChildOf relationship between an item and its elemental parts that are assigned their own DOI (limited parent relation typing)
General typed relations: explicitly typed relation between an item with a Crossref DOI and an item with one of several possible identifiers.
Relationship types for associated research objects: intra-work (within a work)
Reciprocal relationship types
Relationship types for associated research objects: inter-work (between works)
Reciprocal relationship types
Related material, such as a protocol
Supplement, such as a dataset generated as part of research results
General typed relations
This service allows for the creation of a typed relationship between an item with a Crossref DOI and another content item. The other item may be represented by another Crossref DOI, a DOI from some other Registration Agency, or an item not identified with a DOI. When DOIs are used, the deposit process will fail if the DOI does not exist. Non-DOI identifiers are not verified.
When DOIs are used, a bidirectional relation is automatically created by Crossref when a relation is created in the deposit of one item in a pair. The DOI with metadata creating the relation is said to be the claimant, the other item does not need to have its metadata directly contain the relationship.
Example: translated article
A single journal article is published in two languages with each being assigned its own DOI. In this factious example both are published in the same journal. The original language instance has metadata that contains no indication of the translation instance. The alternative language instance includes in its metadata a relation to the original language instance. Here is a screenshot of the relevant section in the code. Please refer to the code snippet below to see it in context.
<title>Um artigo na língua original, que passa a ser o inglês</title>
<original_language_title language="en">An article in its original language which happens to be English</original_language_title>
<person_name sequence="first" contributor_role="author">
<description>Portuguese translation of an article</description>
<intra_work_relation relationship-type="isTranslationOf" identifier-type="doi">10.5555/original_language</intra_work_relation>
Example: book review
This example has a book review published as an article in the journal The Holocene. The article’s title, taken from the publisher’s site is “Book Review: Understanding the Earth system: compartments, processes and interactions” where this book has the DOI https://doi.org/10.1007/978-3-642-56843-5.
A: The current metadata for the review article gives no indication of the actual book being reviewed:
B: Modifications to the review’s metadata show how it would include a relationship to the book. Here is a screenshot of the relevant section in the code. Please refer to the code snippet below to see it in context.
Component records are often registered for figures, tables, and supplemental materials associated with a journal article.
Constructing component deposits
Components may be deposited along with their parent DOI or they can be deposited by themselves in a separate XML file as a stand-alone component. Components have their own metadata which is distinct from that of the parent DOI(s).
Components may belong to more than one parent item. For example, two journal articles may include the same component DOI.