Research Metrics: Journal Metrics

JCR - Impact Factors

JCR contains:  Most frequently cited journals in a field, Highest impact journals in a field, Largest journals in a field

Published annually in two editions:

JCR Science Edition contains data about more than 8,000 journals in science and technology.

JCR Social Sciences Edition contains data about more than 2,600 journals in the social sciences.

View the Journal Citation Reports Quick Reference Card (pdf).

Eigenfactor

"A journal's Eigenfactor score is our measure of the journal's total importance to the scientific community."

SCImago - SJR

Rank, Analyze, Compare, and Visualize journals and countries - based on information from Scopus.

Some Definitions

Journal Impact Factor

Citations to articles from the most recent two full years, divided by the total number of articles from the most recent two full years.  "How much is this journal being cited during the most recent two full years?"

5-Year Journal Impact Factor

Citations to articles from the most recent five full years, divided by the total number of articles from the most recent five full years. "How much is this journal being cited during the most recent five full years?"

Journal Immediacy Index

Citations to articles from the current year, divided by the total number of articles from the current year.  "How much is this journal being cited during the current year?"

Journal Cited Half-Life

For the current Journal Citation Reports year, the median age of journal articles cited.  "What is the duration of citation to articles in this journal?"

Eigenfactor Score

Similar to the 5-Year Journal Impact Factor, but weeds out journal self-citations.  It also, unlike the Journal Citation Reports impact factor, cuts across both the hard sciences and the social sciences.

Article Influence

The Eigenfactor score divided by the number of articles published in journal.  "I know how impactful the journal as a whole is, but what about the average individual article in the journal?"

SJR - Scientific Journal Rankings (SCImago)

This metric doesn't consider all citations of equal weight; the prestige of the citing journal is taken into account.

SNIP - Source-Normalized Impact per Paper

SNIP weights citations based on the number of citations in a field. If there are fewer total citations in a research field, then citations are worth more in that field.