Abstracting & Indexing

What are A&I services and how do they work?

Speeding up searches: Abstracting & indexing (A&I) services unlock the content of academic journals and ebooks using metadata and abstracts, thereby improving the ease of use of academic literature. The metadata used in abstracting & indexing services includes the title, author, publication date, journal title, volume and issue number, page numbers, subject area, keywords, DOI, etc. Inputting search criteria brings up the metadata and abstracts of relevant articles, chapters, and books, along with links to the full-text versions.

If the user already has full-text access or if the relevant publications are available in open access formats, the full-text versions can be accessed immediately. Otherwise, readers are usually provided with information from the publisher or rights holder on how to access the publication.

What Abstracting & Indexing services are there?


At present, there are around 200 corporations and institutions offering A&I services with around 400 individual databases. These include:

Academic services covering all subject areas:
Web of Science (Clarivate)
Scopus (Elsevier)
Google Scholar

Corporations with dozens of often specialized databases:
EBSCOhost
ProQuest/CSA

Services in specific subject areas:
Chemical Abstracts Service (SciFinder)
Index Theologicus
Philosopher's Index
PubMed

Services dedicated exclusively to open access publications:
Directory of Open Access Journals (DOAJ)
Directory of Open Access Books (DOAB)

At De Gruyter, we collaborate with almost all abstracting & indexing services and are constantly expanding our database provision for the benefit of our readers.

The Journal Impact Factor (JIF) and other scientometric indicators


Clarivate Analytics’ Journal Impact Factor (JIF) is the most widely used scientometric/bibliometric indicator for journals. The JIF measures the average number of citations received by a journal’s articles published in the two preceding years. The higher the score, the more influential the journal. The score range however differs significantly from discipline to discipline.

The results for the previous year are published in the Journal Citation Reports around the middle of each year.

CiteScore, SCImago Journal Rank, and Source Normalized Impact per Paper are three other scientometric journal indicators that are now well established. They are all based on the Scopus database and publish the previous year’s results every summer.

  • CiteScore measures the average number of citations received by a journal’s articles. Unlike the Journal Impact Factor, however, it assesses citations over a three-year period, rather than a two-year period.
  • SCImago Journal Rank (SJR) not only considers the number of citations received by a journal’s articles, but also the importance of the journals in which they were cited. The SJR scores are calculated using an algorithm based on Google PageRank.
  • Source Normalized Impact per Paper (SNIP) measures citations in relation to the total number of citations in a given subject area. SNIP assesses the ratio between the average number of citations received by a journal’s articles and the citation potential in the relevant subject. This makes it possible to directly compare journals across different subject areas.

You can find the scientometric scores for our journals on the relevant product pages of our website.