A large-scale comparison of social media coverage and mentions captured by the two altmetric aggregators- Altmetric.com and PlumX

The increased social media attention to scholarly articles has resulted in efforts to create platforms & services to track and measure the social media transactions around scholarly articles in different social platforms (such as Twitter, Blog, Facebook) and academic social networks (such as Mendeley, Academia and ResearchGate). Altmetric.com and PlumX are two popular aggregators that track social media activity around scholarly articles from a variety of social platforms and provide the coverage and transaction data to researchers for various purposes. However, some previous studies have shown that the social media data captured by the two aggregators have differences in terms of coverage and magnitude of mentions. This paper aims to revisit the question by doing a large-scale analysis of social media mentions of a data sample of 1,785,149 publication records (drawn from multiple disciplines, demographies, publishers). Results obtained show that PlumX tracks more wide sources and more articles as compared to Altmetric.com. However, the coverage and average mentions of the two aggregators vary across different social media platforms, with Altmetric.com recording higher mentions in Twitter and Blog, and PlumX recording higher mentions in Facebook and Mendeley, for the same set of articles. The coverage and average mentions captured by the two aggregators across different document types, disciplines and publishers is also analyzed.