Explanation of terms and methodology

Sources

Web of Science, CrossRef and Altmetric

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 and CrossRef. 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.

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.