Defining citations

Within the COBISS/SciMet portal, a citation of an publication is a publication that cites the first publication (which is cited in references); in WoS and Scopus, both publications must have the so-called »full record«. A number of pure citations (CI) is a number of citations (TC) without self-citations (AC), which are determined in the WoS or Scopus databases on the basis of authors' codes in these systems or on the basis of a standardized name of the author if a certain author does not have his/her own code in the system. The number of pure citations per author (CIAu) is the number of pure citations divided by the number of authors of the publication (N) or by the number 10 * log(N) for N > 10 (authors from the WoS or Scopus databases are taken into consideration as all the authors are not always entered in the COBISS system).

A self-citation is determined for an publication and not for an individual author; it is created if at least one author's code exists, which is the same in the cited publication and in the publication that cites the first publication. In that case, all authors of one publication get the same number of citations and self-citations for this publication, whereby the publication in any (personal or group) report within the COBISS/SciMet portal will always have the same number of citations and self-citations for a certain citation window. 

For example, in the two publications below, the second publication is considered as self-citation for all authors of the first publication, including authors Grosel A. and Scancar J., although they are not co-authors of the publication.

The cited publication: 
Kranjc, S., Cemazar, M., Grosel, A., Scancar, J., Sersa, G., 2003. Electroporation of LPB sarcoma cells in vitro and tumors in vivo increases the radiosensitizing effect of cisplatin.V: Anticancer Research, 23(1 A), pp. 275-281. 

The publication citing the above publication: 
Sedlar, A., Kranjc, S., Dolinsek, T., Cemazar, M., Coer, A., Sersa, G., 2013. Radiosensitizing effect of intratumoral interleukin-12 gene electrotransfer in murine sarcoma. V: BMC Cancer, 13.

In contrast to the COBISS/SciMet portal, when evaluating scientific performance according to the ARRS methodology, self-citations are defined only on the basis of the author's publications recorded in the bibliographic records of the COBISS system; until 2014, the COBISS system enabled the entry of the first author and of up to 10 co-authors of the publication.
Consequently, differences in the number of researchers' self-citations on the COBISS/SciMet portal and in the SICRIS. system appear. For different sets of authors considered when comparing the publication and its citation, the following three citation types can be defined:

  • common self-citations (SA), identified by comparing identifiers of all the co-authors of the publication in WoS and/or Scopus with identifiers of all the co-authors of its citation in the WoS and/or Scopus database;
  • author's self-citations (AA), identified by comparing the identifier of the first author of the publication in WoS and/or Scopus with identifiers of all the co-authors of its citation in the WoS and/or Scopus database;
  • COBISS self-citations (CA), identified by establishing the identifiers of all co-authors of the publication in the COBISS system with the identifiers of all the co-authors of its citation in the COBISS system; if the citation is not processed in the COBISS system, the citation is not considered to be a self-citation of the publication. 

For the publications by researchers registered in the SICRIS system published in WoS and Scopus between 1996 and 2013, differences in the number of self-citations, the share of self-citations in view of the total number of citations and the average number of self-citations per publication can be noted for all the three types of self-citations.

Source: Budimir, G et. al. Samocitiranost objav slovenskih raziskovalcev v podatkovnih zbirkah Web of Science in Scopus za obdobje 1996–2013


The h-index is a number, which was proposed in 2005 by the Argentine American physicist Jorge Eduardo Hirsch to measure the performance of individual researchers. Within the COBISS/SciMet portal, the h-index represents the number of publications that were cited at least h-times, whereby the self-citations are not taken into account, in contrast to h-index in the WoS and Scopus system, where the h-index is calculated on the basis of all citations. 

For particular entity or entities (researchers, groups of researchers, current project or programme, research organization, author with a registered code or identification number of author from the CONOR.SI authority database, Slovene university, or serials), the h-index is calculated on the basis of ordered list of linked publications in the selected period of published publications and the citation window (Display parameters). The list is arranged in the descending order by the number of pure citations. For example, in the table below, the h-index is 3, as there are three publications in the list that have at least three pure citations, and the other publications have less than three.

  1. Organic and inorganic relaxor ferroelectrics with giant electrocaloric effect V: Applied physics letters, 2010. CI=7 
  2. Multiferroic magnetoelectric fluorides V: Journal of physics, Condensed matter, 2011. CI=6 
  3. Analytical prediction of size-induced ferroelectricity in BaO nanowires under stress V: Physical review. B, Condensed matter and materials physics, 2010. CI=3 
  4. Upper bounds on the electrocaloric effect in polar solids V: Applied physics letters, 2011. CI=2 
  5. 93Nb NMR and Fe3+ EPR study of local magnetic properties of magnetoelectric Pb(Fe1/2Nb1/2)O3. V: Materials research bulletin, 2010. CI=1
  6. Nonlinear magnetoelectric effect in magnetically disordered relaxor ferroelectrics. V: Ferroelectrics, 2010 1 7. Solar orbital power. V: Energy, 2011. CI=1