Altmetrics are alternative metrics derived from open web resources. They measure the number of times a research output is tweeted, downloaded, viewed, discussed, etc., pointing to the public or social visibility of the output.
They add to the variety of available indicators of the impact and influence of a research output.
Altmetrics offer researchers who do not publish in academic journals, or who work in disciplines that are not associated with the accumulation of citations in academic resources, an alternative means of demonstrating the reach and significance of their work. Altmetrics can also be used to complement traditional measures of impact.