Table 1 Basic statistics of studied datasets. Temporal network data on calls and messages from the Copenhagen Network Study [51, 52] (calls & sms), online social network messages at the University of California, Irvine [53] (msg), emails at a European research institution [54] (email), and our crawl of keyword-restricted retweets and mentions in Twitter (retweets & mentions) (see Additional file 1 Section S2). Table shows the number of events E, links L, and nodes N, as well as the fraction of reciprocations over a link, \(p(E_{rec})\), and the fraction of links having at least one reciprocation, \(p(l_{rec})\) (see Additional file 1 Section S1). Most channels (apart from Twitter) show significant levels of temporal reciprocity

From: Temporal patterns of reciprocity in communication networks