Altmetrics are sets of new emerging data sources that measure online social visibility of research artifacts through either lay or scholarly networks. They attempt to paint a fuller picture of the communication and impact of research outputs beyond the traditional article, such as datasets and software.
Altmetrics can be measures such as news coverage, blog posts, tweets and other forms of measureable social media sharing. They also include longer term markers such as download statistics for articles, conference presentation views on SlideShare, dataset downloads and inclusion in online reference management systems.
Altmetrics can be applied at the journal, researcher and article level. Altmetrics are defined by the source of the data, not their granularity.
Altmetrics tools are often downloadable web-based applications. Some are free and others are commercial products.
Tools you can use
ImpactStory collects and aggregates data from multiple sources across the web to produce a single impact report. Sources include Facebook, PLoS, SlideShare, Topsy (for tweets), Mendeley, delicious, CiteULike, Scopus, Wikipedia, PubMed and more.
PLoS Impact Explorer is a demo from Altmetric which uses data from Scopus. Sources include social media, reference managers, blogs, mainstream media outlets (The New York Times) as well as major non-English-language publications.
Plum Analytics is a company that captures and correlates metrics at the group/collection level (e.g. lab, department, museum or journal) by usage, captures, mentions, social media, and citations.