The impact factor of a journal is the average number of citations of articles published in that journal in previous years. The higher the value, the more prestige a journal has. This number gains content when compared to the impact factors of other journals in the same field.
Web of Science: impact factors of journals in Web of Science (for exact and social sciences) can be found in the Journal Citation Reports. You can look up the impact factor of a particular journal, or a list of journals for a (sub)discipline, via Browse by Journal > Select categories.
Scopus: the impact of journals in Scopus, for exact sciences, social sciences and humanities, is indicated with a CiteScore. This can be found in Scopus via Sources. Search by Subject area, Title, Publisher or ISSN.
Scimago journal rank: this indicator shows the total number of articles quoted in one particular journal and takes into account the importance and prestige of the quoting journals.
Eigenfactor: the average number of citations of articles published in a certain journal in the past 5 years. In the Eigenfactor the prestige of the journals in which the citations have been published is taken into account, namely the number of quotations from those journals. The Eigenfactor of a journal can be found on the Eigen-website and in the Journal Citation Reports.
The impact factor of legal journals can be found on the website Law Journals: Submissions and Ranking. Choose journal name words and tick IF to find the impact factor of a particular journal. For a list of journals: choose a subject and/or country and tick IF.
SciVal shows the impact of the publications of UvA employees in Scopus. To consult SciVal, you need an Elsevier account, which is free of charge for UvA students and employees. You can see the impact of groups of researchers within a discipline and of individual researchers. The impact is referred to as the Field-Weighted Citation Impact. For individual researchers you can also find the number of citations per publication and the h-index: a researcher has an index h if the number of h of the publications has been quoted at least h times.
In addition to the traditional indicators, alternative indicators are also available, better known as altmetrics. These indicators measure in particular the degree of social involvement or social impact. This goes beyond quotations in journals. Mentions in (social) media, blogs, Wikipedia, patents and policy documents are also included, as is the number of downloads and views. Altmetrics are available significantly faster than citation counts, because the research can be responded to immediately after publication.
The Library offers UvA researchers a tool, the Altmetric Explorer, with which the alternative indicators can be mapped out.
In CataloguePlus you will often find a link to Altmetrics in articles. In Scopus, ScienceDirect and databases of Ebsco there is a link to PlumX Metrics, also an alternative indicator.