Bibliometrics

Impact Factor (IF) is a measure of the frequency with which a journal article has been cited in a given year. It is calculated annually by Clarivate based on the number of citations to the number of articles in a journal over the last two years for data indexed in the Web of Science Core Collection database.

Impact Factor helps to assess the importance of a journal in comparison with other journals in the same field. Information on the IF value for a journal is provided by the the Journal Citation Reports (JCR) database. 

Five Year Impact Factor was introduced to analyse the impact of a journal over a longer time period. It is calculated in a similar way to the IF but a five-year period is taken into account.

This is a bibliometric indicator of the quality of an author's scientific output and is the sum of the IF values of the journals in which the author has published scientific articles (IF according to the year of publication).

Formula for the Impact Factor in a given year

IFR = number of citations in R for publications from (R-1 + R-2) / number of publications in (R-1 + R-2)
where:
R is the year for which the index is calculated.

Formula for Cumulative Impact Factor

CIF = IF1 + IF2 + ... + IFn
where:
CIF – Cumulative Impact Factor of the author
IFn - Impact Factor of the journal in which the article was published (consistent with the year of publication).

CiteScore is a bibliometric index describing the journals (and other continuing publications such as book series or conference proceedings) indexed in the Scopus database. The CiteScore for a given year is the result of dividing the number of citations of publications from the last four years (including the year for which the index is calculated) by the number of those publications. The CiteScore should only be used to compare journals within a discipline as it is an unnormalised index and does not take into account differences between disciplines.

The CiteScore is calculated once for each year and does not change with subsequent updates of the Scopus database. There is also the CiteScore Tracker, a version of the index used to assess a journal's citation rate in the current year – usually made available in late May/early June. It features the same methodology.

All bibliometric indicators related to the CiteScore can be seen in the Scopus database after selecting a journal title, e.g. in the ‘Sources’ tab.

SCImago Journal Rank (SJR) is an indicator of the prestige of scientific journals that takes into account both the number of citations received by a journal and the prestige of the journals from which the citations originate. The prestige of a journal is derived from a combination of the number of recommendations and the reputation of the works in which the recommendations were published. In the case of the DIS, the field, quality and reputation of the journal have a direct impact on the citation value.
 
The possibility to compare the number of papers published, the number of citations, the SJR index (citation and audience index), the Hirsch index is enabled by the SCImago Journal & Country Rank portal covering journals and national scientific indices compiled from information in the Scopus database (Elsevier).

The SNIP parameter was introduced by Mark Moed in 2010 and is determined from the Scopus database. Source Normalized Impact per Paper allows the citation rate of a journal to be determined in relation to the field that the journal represents. It is the only standardised parameter that takes into account differences due to different publishing practices in different fields.

Adjustment factors included in the method of calculating the parameter include the average frequency of citations in the discipline, as well as the maturation time of the publication (how much time elapses from publication to the peak of citations) or the percentage of self-citation.

In some simplification, it can be said that the SNIP value is the quotient of the average number of citations in a given year relating to publications from the last three years and the citation potential of the discipline. It should be noted that it has a different methodology to the CiteScore, as its calculation takes into account only three types of papers: article, conference paper and review.

Using the SNIP parameter value, one may be tempted to compare journals from different disciplines.

The h-index is a way of measuring scientific achievement, taking into account the number of publications and the number of citations.

It is an indicator that characterises a researcher’s output – it indicates how many h of the author’s publications have been cited ≥ h times.

The Hirsch index can be calculated using the following tools (results obtained from different sources may vary depending on the content of the database used):

• databases on the Web of Science platform,
• Scopus database,
• Publish or Perish tools.

The index was introduced in 2005 by J.E. Hirsch as an indicator of the importance and relevance of all the scientific works of a given author, characterising his or her total output and not just the importance of one particular work. The Hirsch index measures the ability to publish frequently cited papers. This index is h when h number of publications have been cited at least h times, e.g. a factor of h = 10 when an author has 10 publications cited at least 10 times.

The source of the ICV index is Index Copernicus International Journals Master Lists. This reference database provides up-to-date Index Copernicus Value (ICV) values for individual titles, index projections for the following year, information on the journal’s publishing address and website, language of publication, indexation in international databases.

The FWCI is a standardised index generated using the SciVal analysis tool. It expresses the ratio of the number of citations of a publication to the global average number of citations obtained by all similar publications indexed in the Scopus database. It takes also into account the specificity of the discipline, as well as the type and year of publication.

The FWCI is used for comparisons between different scientific disciplines.

1. Agro
2. BazEkon
3. BazHum
4. BazTech
5. Bibliographica Cartographica
6. Biological Abstracts/ BIOSIS Preview/ BIOSIS
7. CEEOL – Central and Eastern European Online Library
8. CEJSH – The Central European Journal of Social Sciences and Humanities
9. Chemical Abstracts (CAS)
10. Cold Regions Science and Technology Bibliography
11. Compendex 
12. DBLP Computer Science Bibliography
13. DOAJ Directory of Open Access Journals
14. EMBASE
15. ERIC
16. ERIH PLUS
17. GeoArchive (Geosystems)
18. Geobase
19. GeoRef: Bibliography & Index of Geology
20. INSPEC 
21. IREON Gateway – The International Relations and Area Studies Gateway
22. JSTOR
23. MathSciNet (Mathematical Reviews)
24. Polska Bibliografia Lekarska
25. ProQuest/CSA
26. PubMed / PubMed Central / Medline
27. Referativny Zhurnal / VINITI
28. SPIRES
29. SPORTDiscus
30. The Philosopher's Index
31. Zentralblatt MATH
32. Zoological Record.