Library:Citation Analysis & Impact Factors/Metrics
Metrics
Traditional scholarly metrics count publications and citations in journals, books, etc. Altmetrics are new metrics that count numbers of downloads, views, comments on scholarly websites and blogs, etc.
Scholarly Metrics
Individual author/article citation counts Citation Tracking (CT) counts the number of times an individual article or a particular author has been cited by other scholars. Large numbers are associated with greater impact and influence. Article and author level citation counts are available on Web of Science, Google Scholar, PLoS, BioMed Central, plus numerous discipline-specific databases.
H-index A measure of author influence, an h-index is the number where the number of articles published by an author intersects on a graph with the number of citations for each article. For instance, an author with h-index of 10 has published 10 papers that have been cited at least 10 times each. The h-index is the first (and most well-known) of many author metrics. Available on Web of Science and Google Scholar if the scholar has created a user profile.
Journal Impact Factor (used by ISI Web of Science) A Journal Impact Factor (JIF) is measured by dividing the number of current citations a journal has in a given year, by the number of articles published in the two previous years. The JIF is used to indicate the relative importance of a journal within a given field and a higher JIF is seen as providing more “authority” or “weight” to a researchers’ work.
Eigenfactor A non-commercial alternative to ISI Web of Science's JIF. The Eigenfactor algorithm also takes into account the significance of the citations coming into a journal so that citations from important journals are weighted more highly.
Acceptance Rate Acceptance rate compares the number of articles selected for publication to the number of articles submitted. For example, the very prestigious journal Nature publishes fewer than 10% of the articles submitted. In general, a low acceptance rate is associated with high prestige. Not all journals publish their acceptance rates, but in many cases it is included in the "instructions to authors" section of the journal.
Concerns Use of the Journal Impact Factor as "the primary parameter with which to compare the scientific output of individuals and institutions" has been criticized by a number of scholars and organizations, most notably here.
Most scholarly metric tools include only a small fraction of citations that appear in books or book chapters: the work of Humanities and Social Sciences scholars is not accurately reflected.
Alternative Metrics
Download counts and View Counts These article level metrics count the number of times an article has been downloaded and the number of times that it has been viewed. Download counts can be used to demonstrate use of articles for purposes other than citation such as education, background research, presentation, or use in grey literature such as white papers or reports. Download and view counts are available for many, but certainly not all journals.
Counting Citations in non-scholarly media Altmetric.com tracks tweets, blog posts, news stories and other content that mention scholarly articles.
Counting Citations to Additional Publication Types For example, impactstory.org includes datasets, software, slide decks, figures and posters.
Authority scores (e.g. Klout)
Authority scores attempt to measure how many people you reach through your own contacts, their amplified reach (e.g. how many people are followed by people who follow you on Twitter) and how often your content elicits a response (i.e. a comment or reply).