Publication and Research Impact

Journal metrics use citation data to rank and compare scholarly journals. Citation analyses are based on the premise that the number of citations is an indication of the importance of a journal.

The status of a journal is commonly determined by two factors:
1. Popularity (e.g. number of citations a journal receives)
2. Prestige (e.g. sources of a journal’s citations)

Several major citation databases have devised metrics based on citations to rank the journals.  Below we explain how some of these citations work.

Scopus has several journal indicators available .

• SJR (SCImago Journal Rank) – measures the scientific prestige of a scholarly journal by assigning a relative score based on a citation network.
• SNIP (Source Normalized Impact per Paper) – measures contextual citation impact by weighting citations based on the total number of citations in a subject field.
• IPP (Impact Per Publication) is the average number of citations received in a particular year by papers published in the journal during the three preceding years.
• CiteScore is the average number of citations a journal has received over three previous years.

Offers free access to bibliometric data for scientific journals, calculated by Leiden University's Centre for Science and Technology Studies.

Ranks journals based on citations from articles indexed in Google Scholar. Journals are categorised by subject areas and ranked by their h5-index, which measures the visibility and influence of recent articles. The top 100 publications in several languages can be browsed to see which articles were cited the most and by whom.

Consists of two parts for Sciences and Social Sciences, ranking top journals based on citation behaviour. The Journal Impact Factor (JIF) is a measure used to evaluate journals, calculated by Thomson Reuters Web of Science. JIF helps researchers identify where to publish for increased recognition and impact. JCR includes references from journals indexed by Web of Science.

• Individual articles should never be judged solely on the impact factor or other metrics for the journal in which an article is published.
• All journals have a spread of citations, and even the best journals have some articles that are never cited.
• Citation counts alone do not indicate the quality of the citations or the publication e.g. a work may be highly cited because it is controversial; this can distort the impact factor of a journal. Often these journals tend to have high higher rates.
• Analyses are limited to the journals listed in the database you are using, e.g. JCR results are limited to the journals in the Thomson Reuters database, explaining why many journals do not have an Impact Factor.
• Different journal citations databases use different metrics.
• Omissions can occur with author profiles in journals therefore they should be checked for accuracy.
• Citations may be biased e.g. English language and review journals tend to be cited more frequently than works in other languages; authors may frequently cite their own work or the work of their colleagues.
• Review journals tend to have higher impact factors than original research journals in the same field because they tend to be cited more frequently.
• Only research articles, technical notes and reviews are “citable” items. Editorials, letters, news items and meeting abstracts are “non-citable items” and so do not contribute to impact factors and other metrics calculated from citation data.