标题： 有向闭包过程在混合社会信息网络中的应用，以及对推特上链接形成的研究 显示英文标题

标题： The Directed Closure Process in Hybrid Social-Information Networks, with an Analysis of Link Formation on Twitter

摘要： 它经常被当作一种工作假设，即信息网络中的有向链接通常是通过“捷径”连接源和目标之间的两步路径形成的——这是一种类似于社会网络中三元闭合过程的隐式“链接复制”。 尽管这一假设在诸如优先附加等理论模型中发挥了作用，但迄今为止却很少有直接的实证研究。 在这里，我们开发了一种形式化方法和研究这类有向闭合过程的方法，并提供了其在Twitter链接形成中重要作用的证据。 然后，我们分析了一系列旨在捕捉我们在Twitter数据中观察到的相关结构现象的有向闭合模型。 显示英文摘要

摘要： It has often been taken as a working assumption that directed links in information networks are frequently formed by "short-cutting" a two-step path between the source and the destination -- a kind of implicit "link copying" analogous to the process of triadic closure in social networks. Despite the role of this assumption in theoretical models such as preferential attachment, it has received very little direct empirical investigation. Here we develop a formalization and methodology for studying this type of directed closure process, and we provide evidence for its important role in the formation of links on Twitter. We then analyze a sequence of models designed to capture the structural phenomena related to directed closure that we observe in the Twitter data.