New online today. Here’s what Scopus/Elsevier sent us and also posted online.
The metrics provide alternative, transparent and accurate views of the citation impact a journal makes, and are all available for free download at www.journalmetrics.com.
The impact metrics are based on methodologies developed by external bibliometricians and use Scopus as the data source.
Source Normalized Impact per Paper (SNIP)
SNIP measures contextual citation impact by weighting citations based on the total number of citations in a subject field. The impact of a single citation is given higher value in subject areas where citations are less likely, and vice versa. As a field-normalized metric SNIP offers researchers, authors and librarians the ability to benchmark and compare journals from different subject areas. A component of the SNIP calculation is the raw Impact per Publication (IPP) which measures the ratio of citations per article published in the journal.
SCImago Journal Rank (SJR)
SJR is a prestige metric based on the idea that ‘all citations are not created equal’. With SJR, the subject field, quality and reputation of the journal have a direct effect on the value of a citation. It is a size-independent indicator and it ranks journals by their ‘average prestige per article’ and can be used for journal comparisons in the scientific evaluation process.
Impact per Publication (IPP)
The IPP measures the ratio of citations in a year (Y) to scholarly papers published in the three previous years (Y-1, Y-2, Y-3) divided by the number of scholarly papers published in those same years (Y-1, Y-2, Y-3). The IPP metric is using a citation window of three years which is considered to be the optimal time period to accurately measure citations in most subject fields. Taking into account the same peer-reviewed scholarly papers only in both the numerator and denominator of the equation provides a fair impact measurement of the journal and diminishes the chance of manipulation.
The SNIP is developed by Leiden University’s Centre for Science & Technology Studies (CWTS). The SJR is developed by the SCImago research group in Spain.
Direct to JournalMetrics.com
See Also: Journal Metrics FAQ