In the era of social media, people frequently share their own opinions online on various issues and also in the way, get exposed to others' opinions. Be it for selective exposure of news feed recommendation algorithms or our own inclination to listen to opinions that support ours, the result is that we get more and more exposed to opinions closer to ours. Further, any population is inherently heterogeneous i.e. people will hold a varied range of opinions regarding a topic and showcase a varied range of openness to get influenced by others. In this paper, we demonstrate the different behavior put forward by open- and close-minded agents towards an issue, when allowed to freely intermix and communicate. We have shown that the intermixing among people leads to formation of opinion echo chambers i.e. a small closed network of people who hold similar opinions and are not affected by opinions of people outside the network. Echo chambers are evidently harmful for a society because it inhibits free healthy communication among all and thus, prevents exchange of opinions, spreads misinformation and increases extremist beliefs. This calls for reduction in echo chambers, because a total consensus of opinion is neither possible nor is welcome. We show that the number of echo chambers depends on the number of close-minded agents and cannot be lessened by increasing the number of open-minded agents. We identify certain 'moderate'-minded agents, who possess the capability of manipulating and reducing the number of echo chambers. The paper proposes an algorithm for intelligent placement of moderate-minded agents in the opinion-time spectrum by which the opinion echo chambers can be maximally reduced. With various experimental setups, we demonstrate that the proposed algorithm fares well when compared to placement of other agents (open- or close-minded) and random placement of 'moderate'-minded agents.

翻译：在社交媒体时代，人们频繁在线分享各类议题的个人观点，也因此接触到他人的看法。无论是新闻推送算法的选择性曝光机制，还是我们自身倾向于倾听与自己观点相符的意见，结果都是我们越来越多地接触到与自己相近的观点。此外，任何人群本质上都是异质的——人们对某个议题持有不同范围的看法，并展现出不同程度接受他人影响的开放性。本文展示了开放型与封闭型代理人面对议题时，在自由混合交流中所呈现的不同行为模式。研究表明，人群之间的交流会导致意见回声室的形成，即由持相似观点且不受室外人群影响的成员构成的小型封闭网络。回声室对社会显然有害，因为它阻碍了所有成员间的健康自由交流，从而抑制意见交换、传播错误信息并加剧极端主义倾向。这要求我们减少回声室——因为意见的完全共识既不可实现也不受欢迎。我们证明回声室的数量取决于封闭型代理人的数量，且无法通过增加开放型代理人来减少。我们识别出某些具有操纵和减少回声室能力的"温和"型代理人。本文提出了一种在意见-时间频谱上智能部署温和型代理人的算法，可最大程度减少意见回声室。通过多种实验设置，我们证明该算法相较于部署其他类型代理人（开放型或封闭型）或随机部署温和型代理人，均展现出更优性能。