Altmetric is a small London-based start-up focused on making article level metrics easy. We believe that:
We've created and maintain a cluster of servers that watch social media sites, newspapers and magazines for any mentions of scholarly articles.
In mid January 2012 we were tracking approximately three thousand unique papers a day. We have broad coverage and are getting better every month - we can track articles from hundreds of different publishers, preprint databases and institutional repositories. If somebody has recently tweeted, blogged or posted a public link to your paper then we quite possibly know about it.
We clean up the data, disambiguate articles and give each one an Altmetric score as described below.
The Altmetric score is a quantative measure of the quality and quantity of attention that a scholarly article has received. It is derived from three main factors:
|The score for an article rises as more people mention it. We only count one mention from each person per source, so if you tweet about the same paper more than once Altmetric will ignore everything but the first.||Each category of mention contributes a different base amount to the final score. For example, a newspaper article contributes more than a blog post which contributes more than a tweet.||We look at how often the author of each mention talks about scholarly articles, whether or not there's any bias towards a particular journal or publisher and at who their audience is.
For example, a doctor sharing a link with other doctors counts for far more than a journal account pushing the same link out automatically.
Articles for which we have no mentions are scored 0. Though the rate at which scientists are using social media in professional context is growing rapidly most articles will score 0; the exact proportion varies from journal to journal but a mid-tier publication might expect 30 - 40% of the papers it publishes to be mentioned at least once, with the rate dropping rapidly for smaller, niche publications.
The score has an important limitation: if the article was published before July 2011 we'll have missed any transient mentions of it, tweets in particular, so its score won't be accurate, rather a lower bound of the attention received.
The number in the center of the donut is the Altmetric score, described above. The colours surrounding it reflect the mix of sources mentioning that score - blue for Twitter, yellow for blogs, red for mainstream media sources and so on.
Hover your mouse pointer over the donut to see a breakdown of different sources.