Sources: Web of Science, CrossRef, Scopus, WebTrends, and Altmetric
Frequency of updates: In most cases, our metrics data is updated hourly, In some cases, such as page views, the data is not available the first 48 hours after an article is published.
Citations
Single number count for article citations from each service's database (may vary by service). The citations counts are reliant on the availability of the individual APIs from Web of Science, CrossRef, and Scopus. These counts are updated daily once they become available. Once a citation count is available, the list of articles citing this one is accessible by clicking on the circle for that citation source.
Page views
A cumulative count of full-text article views that includes HTML views and PDF downloads. These data reflect only usage on the nature.com journal platform, as tracked by WebTrends tagging, and are only for articles published on or after 1 January 2012. NPG content is also available on other third party platforms and in repositories around the world; we are currently not including article usage data from any of these third-party services. The page views data is available 48 hours after online publication and is updated daily.
News, blogs and Google+ posts
The number of times an article has been cited by individual mainstream news sources, blog post, or member of Google+ along with a link to the original article or post. News articles, blog posts and Google+ posts do not always link to articles in a way that can be picked up by aggregators used by Altmetric, so the listed links are not necessarily a reflection of the entire scope of media, blog or Google+ interest. Further, the list of blogs and news sources covered is manually curated by Altmetric and thus is subject to their discretion for inclusion as a scientific blog or media source. The news, blog, and Google+ posts are provided by Altmetric and are updated hourly.
Altmetric score
Altmetric calculates a score based on the online attention an article receives. Each coloured thread in the circle represents a different type of online attention and the number in the centre is the Altmetric score. The score is calculated based on two main sources of online attention: social media and mainstream news media. Altmetric also tracks usage in online reference managers such as Mendeley and CiteULike, but these do not contribute to the score. Older articles will typically score higher because they have had more time to get noticed. To account for this, Altmetric has included the context data for articles of a "similar age" (published within 6 weeks of either side of the publication date of this article).
For a more detailed description of Altmetric, the Altmetric score, and sources used, please see Altmetric's information page.
Twitter demographics
Provides the number of tweets broken down by country of origin for the Twitter account. The geographic breakdown for the twitter sources is provided by Altmetric and is updated hourly.