For a quick introduction to publication metrics, consult the Association of Academic Health Sciences Libraries' Navigating Knowledge, written by Cathy Sarli of Washington University.
The h-index, or Hirsch index, measures the impact of a particular scientist rather than a journal. "It is defined as the highest number of publications of a scientist that received h or more citations each while the other publications have not more than h citations each (Schreiber, 2008)." The h-index is included in Web of Science and Scopus.
The H-index was designed to overcome the problems of traditional citation counting by creating a single calculation that would measure both the number and quality of publications.
It has inspired a number of variants designed to overcome its perceived weaknesses, none of which has gained widespread acceptance yet.
Proposed by Egghe in 2006 to overcome a bias against highly cited papers inherent in the h-index. The g-index is the "highest number of papers of a scientist that received g or more citations, on average" (Schreiber, 2008).
A and R Indexes
The A and R indexes are meant to be used with h and are not stand-alone indexes. The A-index is the average number of citations per "meaningful paper" (Podlubny & Kassayova, 2006). The R-index clarifies the relationship to the h-index formally (Schreiber, 2008).
A free and searchable database, Eigenfactor covers the natural and social sciences and "also lists newsprint, PhD theses, popular magazines and more." The Eigenfactor is now included in Journal Citation Reports.
The website includes an interactive mapping function that shows the relationship of branches of science to each other based on the size of the field and the citations generated by the journals of the field. Rather than the "soft" categories used in Journal Citation Reports, where a journal may be located in one or more categories, Eigenfactor uses a hard category where a journal can only fit in one discipline.
"This site provides information, online papers and resources about Harzing's areas of research: International and Cross-cultural Management. It also presents resources to assist with academic publishing and the assessment of research and journal quality, as well as software to conduct citation analysis."
European Science Foundation's subgroup for the Humanities. Scroll down to see a table that contains links to journal rankings in the Humanities.
This source ranks journals that are indexed by ISI's Science Citation Index. The website allows you to customize your ranking and is interactive.
Source Normalized Impact per Paper (SNIP)
Based on Scopus data, SNIP is a European ranking that attempts to address the problems of varying citation rates among disciplines and the lack of statistics to indicate levels of significant differences.
SCImago Journal & Country Rank (SJR)
A free source that uses data from Elsevier's Scopus database. Includes a "compare" feature that compares journal citation among countries. There is also a "map generator" that shows citation relationships by country. The SJR indicator aims to measure "the current 'average prestige per paper'" of research journals and is one of a new set of journal rangings based on eigenvector centrality (Gonzalez-Pereira 2009) .