Impact factors and journal metrics (also known as bibliometrics) are measures that attempt to quantify the importance of a journal or article in the scholarly literature. These metrics are not without controversy, but are widely used. There are a number of different metrics in use, including:
SCImago Journal and Country Rank, or SJR, is a measure of scientific influence of scholarly journals that accounts for both the number of citations received by a journal and the importance or prestige of the journals where such citations come from.
The SJR indicator, which is inspired by the Google PageRank algorithm, was developed for extremely large and heterogeneous journal citation networks. It is a size-independent indicator and it ranks journals by their ‘average prestige per article’ and can be used for journal comparisons in science evaluation processes.
SJR calculation uses data provided by Scopus.
Google Scholar Metrics uses the H-Index formula to rank journals. The Metrics Home Page lists the top 100 h5-index ranked publications in English.
"The h5-index is the h-index for articles published in the last 5 complete years. It is the largest number h such that h articles published in 2010-2014 have at least h citations."
Because disciplines have varying publishing models and expectations, comparing journal citation indices across research areas is not recommended. However, Google Scholar Metrics also provides h5-index ranked lists by subject area. Researchers can select language, discipline category, and, if desired, a subject sub-category.
By clicking on the h5-index for each journal, one can access the references for the most cited articles and the number of times each article was cited within that 5-year period.
Clicking on the Cited by number within each reference provides a list of those articles.
Clicking on an article name can lead to a source and sometimes full text.
Caveat: Google Scholar Metrics is limited to articles indexed in Google Scholar, a database that does not have set journal inclusion parameters. For best results, multiple sources and methods should be used in identifying the most significant journals and articles in a research area.
Direct link to Google Scholar Metrics home page of journal rankings.
Information about Google Scholar Metrics, including coverage and inclusion.
Google Scholar Search Page. Click on Metrics to access journal rankings.
The Eigenfactor™ Score uses a network of citation data to assess the relative importance of journals in the science and social science communities. Journals with many citations from influential journals are rated as influential themselves.
The Article Influence™ Score determines the average influence of a journal's articles.
Score calculation is based on the citations received over a five year period, but it also considers which journals have contributed these citations so that highly cited journals will influence the network more than lesser cited journals. References from one article in a journal to another article from the same journal are removed, so that Eigenfactor Scores are not influenced by journal self-citation.
Since the number and frequency of citations vary by discipline, the Eigenfactor algorithm adjusts for these differences.
In addition to articles from scholarly journals, Eigenfactor also includes newspaper articles, theses, popular magazines and other items in its reference material.
More information on bibliometrics and working with impact data can be found at:
