Publishing and Perishing in the Twenty-First Century
0The creation of quantifiable measures of the impact and relative importance of a publication, a journal, an individual researcher�s output, or a university is close kin to ranking algorithms in information retrieval. Eugene Garfield developed the journal impact factor (IF) a half-century ago based on a two-year window of citations. And more recently, Jorge Hirsch invented the h-index to quantify an individual�s productivity based on the distribution of citations over one�s publications. There are also several competing �world university ranking� systems in wide circulation. Most traditional bibliometrics seek to build upon the citation structure of scholarship in the same manner that PageRank uses the link structure of the web as a signal of importance, but new approaches (or Alt Metrics) are now seeking to harness usage patterns and social media to assess impact.