The Scientist (registration required) reports about a decision of the Public Library of Science (PLoS) to release other measures for some of its articles over the next several months.  For journals, the metric for the quality of the publication is a citation index, which notes the ‘impact factor’ of the publication and its articles.  What PLoS intends to do is put up several different measures for its articles – including “usage data, page views, citations from Scopus and CrossRef, social networlking links, press coverage, comments, and user ratings for each of PLoS ONE’s thousands of articles.”  From there it will be up to the users to see what metrics are used, and to what effect.  As PLoS is not currently listed in the major science-oriented citation index, this is a necessary measure to help demonstrate the value of its research, independent of the benefits of open access.