Article-level metrics
In scientometrics — the quantitative study of scientific activities — article-level metrics refer to measures at the level of individual articles, as opposed to journal-level metrics like the Journal Impact Factor, or other metrics at the levels of individual researchers, research project, research institutions or countries.
Typical article-level metrics include the number of citations garnered by an individual article or, for articles available electronically, the number of social bookmarks, the number of trackbacks to the article from blog posts, the number of views online, or the number of downloads in various formats (e.g. PDF or XML). Some reference managers also allow to track the number of printouts or the time an article is displayed in an active window. All these data can technically be made public, and some publishers have started to do so.