Tidsskriftsindikatorer, der baseres på citationer, udvikles ved forskellige forlag og organisationer og bygger på data fra enten Web of Science (Clarivate) eller Scopus (Elsevier)
Indikatorerne baseres på forholdet mellem citationer til et tidsskrift og antallet af artikler i tidsskriftet i en afgrænset periode. Nogle af udregningerne forsøger at tage højde for forskelle i citationspraksis inden for forskellige fagområder (AIS, SNIP, SJR), mens andre kun kan bruges til at sammenligne tidsskrifter inden for et afgrænset felt (JIF, IPP).
Der er i de senere år startet en bevægelse, som, via en række anbefalinger, bl.a. ønsker at mindske brugen af tidsskriftsindikatorer som indikator for forskningsimpact (San Francisco Declaration on Research Assessment (DORA)).
Journal Impact Factor bygger på citationer fra Web of Science. Du kan finde JIF via Journal Citation Reports.
"”The Journal Impact Factor (JIF) is a ration which divides a journal’s received citations by a count of its published articles. It’s not a mathematical average, but it does proved an approximation of the mean citation rate for a typical article.”
(https://clarivate.com/academia-government/wp-content/uploads/sites/3/dlm_uploads/2025/06/Journal-Impact-Factor-Quick-Reference-Guide-1.pdf#page=1.14&gsr=0)
Source Normalized Impact per Paper bygger på citationer fra Scopus. Du kan finde SNIP i Scopus og på http://www.journalindicators.com/.
“The source normalized impact per publication, calculated as the number of citations given in the present year to publications in the past three years divided by the total number of publications in the past three years.”
”Citations are normalized in order to correct for differences in citation practices between scientific fields. Essentially, the longer the reference list of a citing publication, the lower the value of a citation originating from that publication. A detailed explanation is offered in our scientific paper.”
(http://www.journalindicators.com/methodology)
Eigenfactor
”The Eigenfactor Score is a reflection of the density of the network of citations around the journal using 5 years of cited content as cited by the Current Year. It considers both the number of citations and the source of those citations, so that highly cited sources will influence the network more than less cited sources. The Eigenfactor calculation does not include journal self-citations.”
Article Influence Score
”The Article Influence Score normalizes the Eigenfactor Score according to the cumulative size of the cited journal across the prior five years. The mean Article Influence Score for each article is 1.00. A score greater than 1.00 indicates that each article in the journal has above-average influence.”
(https://journalcitationreports.zendesk.com/hc/en-gb/articles/28351430970001-Journal-Profile)
SCImago Journal Rank (SJR) bygger på citationer fra Scopus. Du kan finde SJR i Scopus og på https://www.scimagojr.com/.
"SCImago Journal Rank measures weighted citations received by the serial. Citation weighting depends on subject field and prestige (SJR) of the citing serial.”
(scopus.com)
