Many researchers now use social media, particularly Twitter, to promote their publications and to keep up to date with the latest developments. This has fuelled interest in alternatives to citation rates and the h-index for assessing research impact. However, the relationship between these traditional measures and alternative metrics (e.g. altmetrics) – in which publications are scored based on the number of mentions they receive on channels such as blogs and social media – is unclear. In an article in PLOS One, Peoples et al. suggest that articles that generate the most Twitter activity also go on to receive the most citations.
Peoples et al. selected roughly 1,600 primary research articles published between 2012 and 2014 in 20 journals with impact factors higher than three. They then used mathematical modelling to identify the factors that determined how many citations each article would receive. After allowing for the fact that the number of citations increased with time since publication, the authors found a positive correlation between the number of unique tweets about an article and its citation rate. Twitter activity was a more reliable predictor of the number of citations than the 5-year impact factor of the journal in which the article was published. Moreover, articles from journals with the highest impact factors were not necessarily those that generated the most attention on Twitter.
As Peoples et al. acknowledge, “the strong relationships…between Twitter activity and traditional citations are predictive (in a statistical sense), but not necessarily causal.” While tweeting could increase the number of citations, it is also possible that higher quality articles both attract more attention on Twitter and receive more citations because of their high quality.