Demarcating Endogenous and Exogenous Opinion Diffusion Process on Social Networks

Abir De, Sourangshu Bhattacharya, Niloy Ganguly

Abstract: The networked opinion diffusion in online social networks (OSN) is governed by the two genres of opinions-endogenous opinions that are driven by the influence of social contacts between users, and exogenous opinions which are formed by external effects like news, feeds etc. Such duplex opinion dynamics is led by users belonging to two categories- organic users who generally post endogenous opinions and extrinsic users who are susceptible to externalities, and mostly post the exogenous messages. Precise demarcation of endogenous and exogenous messages offers an important cue to opinion modeling, thereby enhancing its predictive performance. On the other hand, accurate user selection aids to detect extrinsic users, which in turn helps in opinion shaping. In this paper, we design CherryPick, a novel learning machinery that classifies the opinions and users by solving a joint inference task in message and user set, from a temporal stream of sentiment messages. Furthermore, we validate the efficacy of our proposal from both modeling and shaping perspectives. Moreover, for the latter, we formulate the opinion shaping problem in a novel framework of stochastic optimal control, in which the selected extrinsic users optimally post exogenous messages so as to guide the opinions of others in a desired way. On five datasets crawled from Twitter, CherryPick offers a significant accuracy boost in terms of opinion forecasting, against several competitors. Furthermore, it can precisely determine the quality of a set of control users, which together with the proposed online shaping strategy, consistently steers the opinion dynamics more effectively than several state-of-the-art baselines.