School of Information Management, Wuhan University, Wuhan, China.
School of Data Science, City University of Hong Kong, Hong Kong, China (Hong Kong).
J Med Internet Res. 2022 Nov 18;24(11):e40701. doi: 10.2196/40701.
Social media provide an ideal medium for breeding and reinforcing vaccine hesitancy, especially during public health emergencies. Algorithmic recommendation-based technology along with users' selective exposure and group pressure lead to online echo chambers, causing inefficiency in vaccination promotion. Avoiding or breaking echo chambers largely relies on key users' behavior.
With the ultimate goal of eliminating the impact of echo chambers related to vaccine hesitancy on social media during public health emergencies, the aim of this study was to develop a framework to quantify the echo chamber effect in users' topic selection and attitude contagion about COVID-19 vaccines or vaccinations; detect online opinion leaders and structural hole spanners based on network attributes; and explore the relationships of their behavior patterns and network locations, as well as the relationships of network locations and impact on topic-based and attitude-based echo chambers.
We called the Sina Weibo application programming interface to crawl tweets related to the COVID-19 vaccine or vaccination and user information on Weibo, a Chinese social media platform. Adopting social network analysis, we examined the low echo chamber effect based on topics in representational networks of information, according to attitude in communication flow networks of users under different interactive mechanisms (retweeting, commenting). Statistical and visual analyses were used to characterize behavior patterns of key users (opinion leaders, structural hole spanners), and to explore their function in avoiding or breaking topic-based and attitude-based echo chambers.
Users showed a low echo chamber effect in vaccine-related topic selection and attitude interaction. For the former, the homophily was more obvious in retweeting than in commenting, whereas the opposite trend was found for the latter. Speakers, replicators, and monologists tended to be opinion leaders, whereas common users, retweeters, and networkers tended to be structural hole spanners. Both leaders and spanners tended to be "bridgers" to disseminate diverse topics and communicate with users holding cross-cutting attitudes toward COVID-19 vaccines. Moreover, users who tended to echo a single topic could bridge multiple attitudes, while users who focused on diverse topics also tended to serve as bridgers for different attitudes.
This study not only revealed a low echo chamber effect in vaccine hesitancy, but further elucidated the underlying reasons from the perspective of users, offering insights for research about the form, degree, and formation of echo chambers, along with depolarization, social capital, stakeholder theory, user portraits, dissemination pattern of topic, and sentiment. Therefore, this work can help to provide strategies for public health and public opinion managers to cooperate toward avoiding or correcting echo chamber chaos and effectively promoting online vaccine campaigns.
社交媒体为疫苗犹豫情绪的滋生和强化提供了理想的媒介，尤其是在公共卫生紧急事件期间。基于算法推荐的技术以及用户的选择性接触和群体压力导致了在线回音室现象，从而使疫苗推广效率降低。避免或打破回音室在很大程度上依赖于关键用户的行为。
本研究旨在开发一个框架，以量化公共卫生紧急事件期间社交媒体中与疫苗犹豫相关的回音室效应对用户在 COVID-19 疫苗或接种方面的话题选择和态度传播的影响；根据网络属性检测在线意见领袖和结构洞桥接者；并探索他们的行为模式和网络位置之间的关系，以及网络位置与基于话题和态度的回音室的关系。
我们调用了新浪微博的应用程序接口来抓取与 COVID-19 疫苗或接种以及微博上的用户信息相关的微博，并采用社会网络分析方法，根据不同互动机制（转发、评论）下用户的信息流网络中的态度，检验基于代表性信息网络的低回音室效应。统计和可视化分析用于描述关键用户（意见领袖、结构洞桥接者）的行为模式，并探索他们在避免或打破基于话题和态度的回音室方面的作用。
用户在疫苗相关话题选择和态度互动方面表现出低回音室效应。对于前者，在转发中同质性比评论中更为明显，而后者则相反。扬声器、复制者和独白者往往是意见领袖，而普通用户、转发者和网络者往往是结构洞桥接者。意见领袖和桥接者都倾向于成为传播多样化话题和与对 COVID-19 疫苗持交叉态度的用户进行交流的“搭桥者”。此外，倾向于附和单一话题的用户可以桥接多种态度，而关注多样化话题的用户也往往可以充当不同态度的桥接者。
本研究不仅揭示了疫苗犹豫中的低回音室效应，还从用户的角度进一步阐明了其背后的原因，为回音室的形式、程度和形成以及极化、社会资本、利益相关者理论、用户画像、话题传播模式和情绪等方面的研究提供了启示。因此，这项工作可以帮助公共卫生和舆论管理者提供策略，以合作避免或纠正回音室混乱，并有效地促进在线疫苗宣传。
