At the journal level, information can be found in catalogs (such as library catalogs like OCLC’s Worldcat) and knowledge bases (which libraries use to manage access to electronic resources via services like link resolvers). You’ll also find journals described in indexes such as the Directory of Open Access Journals (which indexes both journals and individual articles) and the ISSN portal.
At the article level, information can be found in abstracting and indexing databases. Indexes are databases containing descriptions of resources: journal, newspaper, or magazine articles, blog posts, reports, gray literature, and more. Sometimes research databases will include only citations and abstracts, and other times they might include the full text of the resource. Google Scholar is an example that falls into the category of open web indexes, whereas others are your more traditional scholarly databases, which are provided via subscription to libraries. Examples of the latter would be ProQuest Central and JSTOR. There are also open indexes and registries, like the Directory of Open Access Journals and Crossref.
Indexes are populated in various ways: search engine indexes make use of web crawling techniques, in which a computer program traverses links on the web and gathers data which is then put in a structured format. Some indexes might employ human catalogers or indexers to analyze content and produce original structured description. Still others may rely on publisher- or contributor-submitted information.
You can be fairly certain that you’ll find things like title and author recorded in most metadata schemas. However, there are different ways to break down the information. For example, Dublin Core (a common general purpose metadata schema) includes fields for contributor or creator, while a schema like JATS (the Journal Article Tag Suite) includes a field specifically for given name and a field specifically for surname.
Dublin Core
contributor : Maria Pia Rossi
Journal Article Tag Suite (JATS)
contrib
name
surname : Rossi
given-names : Maria Pia
Your metadata will be repurposed in different environments; knowing the requirements of the systems to which you will send metadata (the target schema) can help you collect useful information from your authors and collaborators. Knowing from the beginning that Crossref’s metadata schema breaks up author names into given- and surnames means you can collect information from authors in this format, for example by asking authors to indicate their given- and surnames by filling out a form that provides two distinct fields.
Giving your content unique identifiers helps it stay clear and unambiguous within discovery systems.
Examples of unique identifiers include:
Some metadata schemas also accommodate structured references or citations. For example, Crossref’s schema has a citation element and subelements like journal title, author, volume, and more:
<citation key="ref1">
<journal_title>Current Opinion in Oncology</journal_title>
<author>Chauncey</author>
<volume>13</volume>
<first_page>21</first_page>
<cYear>2001</cYear>
</citation>
Citations can also be unstructured, but putting citation information in specific fields allows for services like Crossref to link directly to the cited material.