What Is a Journal Index, and Why is Indexation Important?

A journal index, also called a ‘bibliographic index' or ‘bibliographic database', is a list of journals organized by discipline, subject, region or other factors.

Journal indexes can be used to search for studies and data on certain topics. Both scholars and the general public can search journal indexes.

Journals in indexes have been reviewed to ensure they meet certain criteria. These criteria may include:

• Ethics and peer review policies
• Assessment criteria for submitted articles
• Editorial board transparency
• Others

What is a journal index?

A journal index, also called a ‘bibliographic index' or ‘bibliographic database', is a list of journals organized by discipline, subject, region or other factors.

Journal indexes can be used to search for studies and data on certain topics. Both scholars and the general public can search journal indexes.

Journals in indexes have been reviewed to ensure they meet certain criteria. These criteria may include:

• Ethics and peer review policies
• Assessment criteria for submitted articles
• Editorial board transparency
• Others

Indexed journals are important, because they are often considered to be of higher scientific quality than non-indexed journals. You should aim for publication in an indexed journal for this reason. AJE's Journal Guide journal selection tool can help you find one.

Journal indexes are created by different organizations, such as:

• Public bodies- For example, PubMed is maintained by the United States National Library of Medicine. PubMed is the largest index for biomedical publications.
• Analytic companies- For example: the Web of Science Core Collection is maintained by Clarivate Analytics. The WOS Core Collection includes journals indexed in the following sub-indexes: (1) Science Citation Index Expanded (SCIE); (2) Social Sciences Citation Index (SSCI); (3) Arts & Humanities Citation Index (AHCI); (4) Emerging Sources Citation Index.
• Publishers- For example, Scopus is owned by Elsevier and maintained by the Scopus Content Selection and Advisory Board. Scopus includes journals in all disciplines, but the majority are science and technology journals.

Key types of journal indexes

You can choose from a range of journal indexes. Some are broad and are considered “general indexes”. Others are specific to certain fields and are considered “specialized indexes”.

For example:

• The Science Citation Index Expanded includes mostly science and technology journals
• The Arts & Humanities Citation Index includes mostly arts and humanities journals
• PubMed includes mostly biomedical journals
• The Emerging Sources Citation Index includes journals in all disciplines

Which index you choose will depend on your research subject area.

Some indexes, such as Web of Science, include journals from many countries. Others, such as the Chinese Academy of Science indexing system, are specific to certain countries or regions.

Choosing the type of index may depend on factors such as university or grant requirements.

Some indexes are open to the public, while others require a subscription. Many people searching for research papers will start with free search engines, such as Google Scholar, or free journal indexes, such as the Web of Science Master Journal List. Publishing in a journal in one or more free indexes increases the chance of your article being seen.

Journals in subscription-based indexes are generally considered high-quality journals. If the status of the journal is important, choose a journal in one or more subscription-based indexes.

Most journals belong to more than one index. To improve the visibility and impact of your article, choose a journal featured in multiple indexes.

How does journal indexing work?

All journals are checked for certain criteria before being added to an index. Each index has its own set of rules, but basic publishing standards include the following:

• An International Standard Serial Number (ISSN). ISSNs are unique to each journal and indicate that the journal publishes issues on a recurring basis.
• An established publishing schedule.
• Digital Object Identifiers (DOIs). DOIs are unique letter/number codes assigned to digital objects. The benefit of a DOI is that it will never change, unlike a website link.
• Copyright requirements. A copyright policy helps protect your work and outlines the rules for the use or sharing of your work, whether it's copyrighted or has some form of creative commons licensing.
• Other requirements can include conflict of interest statements, ethical approval statements, an editorial board listed on the website, and published peer review policies.

To be included in an index, a journal must submit an application and undergo an audit by the indexation board. Index board members (called auditors) will confirm certain information, such as the full listing of the editorial board on the website, the inclusion of ethics statements in published articles, established appeal and retraction processes, and more.

Why is journal indexing important?

As an author, publishing your research in an indexed journal increases the credibility and visibility of your work. Indexed journals are generally considered to be of higher scientific quality than non-indexed journals.

With the growth of fully open access journals and online-only journals, recognizing “predatory” journals and their publishers has become difficult. Indexing a journal in one or more well-known databases is a good sign the journal is credible.

Moreover, more and more institutions are requiring publication in an indexed journal as a requirement for graduation, promotion, or grant funding.

As an author, it is important to ensure that your research is seen by as many eyes as possible. Index databases are often the first places scholars and the public will search for specific information. Publishing a paper in a non-indexed journal could be harmful in this context.

However, there are some exceptions, such as medical case reports.

Many journals don't accept medical case reports because they don't have high citation rates. However, several primary and secondary journals have been created specifically for case reports. Examples include the primary journal, BMC Medical Case Reports, and the secondary journal, European Heart Journal - Case Reports.

While many of these journals are indexed, they may not be indexed in the major indexes, though they are still highly acceptable journals.

Open access and indexation

With the recent increase in open access publishing, many journals have started offering an open access option. Other journals are completely open access, meaning they do not offer a traditional subscription service.

Open access journals have many benefits, such as:

• High visibility. Anyone can access and read your paper.
• Publication speed. It is generally quicker to post an article online than to publish it in a traditional journal format.

Identifying credible open access journals

Open access has made it easier for predatory journal publishers to attract unsuspecting or new authors. These predatory journal publishers often publish any article for a fee without peer review and with questionable ethical and copyright policies. Here we show you eight ways to spot predatory open access journals.

One way to identify credible open access journals is their index status. However, be aware that some predatory journals will falsely list indexes or display logos on their website. It is good practice to make sure the journal is indexed on the index's website before submitting your article to that journal.

Major journal indexing services

There are several journal indexes out there. Some of the most popular indexes are as follows:

Life Sciences and Hard Sciences

• Science Citation Index Expanded (SCIE) Master Journal List
• Scopus
• Engineering Index
• Web of Science (now published by Clarivate Analytics, formerly by ISI and Thomson Reuters)
• Chinese Academy of Sciences (CAS)
• Qualis

Humanities and Social Sciences

• Arts & Humanities Citation Index (AHCI) Master Journal List
• Social Sciences Citation Index (SSCI) Master Journal List

Indexation and impact factors

It is easy to assume that indexed journals will have higher impact factors, but indexation and impact factor are unrelated.

Many credible journals don't have impact factors, but they are indexed in several well-known indexes. Therefore, the lack of an impact factor may not accurately represent the credibility of a journal.

Of course, impact factors may be important for other reasons, such as institutional requirements or grant funding. Read this authoritative piece on the uses, importance, and limitations of impact factors.

Final Thoughts

Selecting an indexed journal is an important part of the publication journey. Indexation can tell you a lot about a journal. Publishing in an indexed journal can increase the visibility and credibility of your research. If you're having trouble selecting a journal for publication, consider learning more about AJE's journal recommendation service.