Evaluating Journals By Journal Metrics 1

The research community has access to a broad range of journal metrics to evaluate the quality of a journal and better understand its performance.

Journal Metrics

Journal metrics are bibliometric indicators focusing on measuring the impact of scholarly journals to allow scholars and researchers to measure, compare, and often rank research and scholarly publications.

Journal metrics are also called journal rankings, journal importance, or a journal’s impact.

Journal Metrics Types

• Impact Factor: calculated by ISI
• IPP: calculated by Scopus
• SNIP: calculated by Scopus
• SJR: calculated by Scopus
• JIF: calculated by ISI

In the present blog post, we will study Impact Factor,  SNIP and IPP; the other two, SJR and JIF will be examined and reviewed in the next blog post.

Impact Factor

Impact Factor is a quantitative metric for evaluating, comparing, and ranking scientific journals in different fields at the national or international level. Eugene Garfield created the Impact factor in the 1950s, which is available through Thompson Reuters’ Journal Citation Reports.

This metric reflects the total citations in a given year to all papers published in the past 2 years divided by the total number of articles and reviews published in the past 2 years; following you see the formula by which the impact factor is calculated:

The Impact Factor is calculated and published only for publications indexed in Thomson Reuters’s Web OF Science database. As such, only ISI journals have a true Impact Factor.

The impact factor was produced by Clarivate (formerly Thomson Reuters), published annually in June.

One of the best ways to find the impact factor of ISI journals is to use this link, where you are needed to enter and search the ISSN number in the relevant box to show the impact factor in recent years.

Although Impact Factor may be a good criterion for measuring the quality of journals, due to its limitations, it should not be used as a standard of comparison between disciplines. Besides, a 2-year publication window is too short for most journals, especially those which has not reached complete maturity.

SNIP

Since 2010 Scopus has offered two journal metrics: the Source Normalized Impact per Paper (SNIP) and the SCImago Journal Rank (SJR), which will be discussed in the next post.

Source-Normalized Impact per Paper (SNIP) measures contextual citation, i.e. citations based on the number of citations in a subject field, using Scopus data. If there are fewer total citations in a research field, then citations are worth more in that field.

SNIP is used to resolve the problems of previous metrics, including Impact Factor for ISI journals, and it can compare journal performance across fields.

Source-Normalized Impact per Paper (SNIP) was created by Professor Henk Moed at the Centre for Science and Technology Studies (CTWS), the University of Leiden for Elsevier, published each June.

IPP

Also known as RIP (raw impact per publication), the Impact per Publication (IPP) “is a measure of the ratio of citations per paper published in the journal and is not normalized for the citation potential in its subject field. IPP is also the numerator in the calculation of SNIP”, according to the Scopus website.

IPP is a number of current-year citations to papers from the previous 3 years, divided by the total number of papers in those 3 previous years.

IPP reduces the likelihood of manipulation, measures the impact of a journal more fairly.

Impact per Publication (IPP) was produced by CWTS, Leiden University based on Scopus data, published each June.

The quality of an academic and research-based paper is calculated and assessed through various methods and ways, most of which are explained in the current blog post. Although these standards are insufficient for the scientific evaluation of any publication, and sometimes problematic, there is a consensus that articles published in ISI journals due to adherence to scientific standards and international publishing rules are currently the main basis for determining the quality and quantity of scientific output.