The Altmetric Attention Score is a value that indicates the amount of attention received by an article across the internet. Sources that are being tracked include the mass media, policy documents, scholarly blogs, wikipedia, open peer reviews, academic syllabi and a variety of social media, including Reddit, Twitter and Facebook. The diversity of the attention sources is represented by the mix of colors in the donut. The value is weighted according to how high profile the attention sources are: with news, blogs and policy papers ranking high, and social media much lower. The precise values can be found here.