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1. Adversarial Classification on Social Networks

   Yu, Sixie; Vorobeychik, Yevgeniy; Alfeld, Scott (January 2018, International Conference on Autonomous Agents and Multiagent Systems)

   The spread of unwanted or malicious content through social me- dia has become a major challenge. Traditional examples of this include social network spam, but an important new concern is the propagation of fake news through social media. A common ap- proach for mitigating this problem is by using standard statistical classi cation to distinguish malicious (e.g., fake news) instances from benign (e.g., actual news stories). However, such an approach ignores the fact that malicious instances propagate through the network, which is consequential both in quantifying consequences (e.g., fake news di using through the network), and capturing de- tection redundancy (bad content can be detected at di erent nodes). An additional concern is evasion attacks, whereby the generators of malicious instances modify the nature of these to escape detection. We model this problem as a Stackelberg game between the defender who is choosing parameters of the detection model, and an attacker, who is choosing both the node at which to initiate malicious spread, and the nature of malicious entities. We develop a novel bi-level programming approach for this problem, as well as a novel solution approach based on implicit function gradients, and experimentally demonstrate the advantage of our approach over alternatives which ignore network structure. 

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2. Adversarial Coordination on Social Networks

   Hajaj, Chen; Yu, Sixie; Joveski, Zlatko; Guo, Yifan; Vorobeychik, Yevgeniy (January 2019, International Conference on Autonomous Agents and Multiagent Systems)

   Extensive literature exists studying decentralized coordination and consensus, with considerable attention devoted to ensuring robustness to faults and attacks. However, most of the latter literature assumes that non-malicious agents follow simple stylized rules. In reality, decentralized protocols often involve humans, and understanding how people coordinate in adversarial settings is an open problem. We initiate a study of this problem, starting with a human subjects investigation of human coordination on networks in the presence of adversarial agents, and subsequently using the resulting data to bootstrap the development of a credible agent-based model of adversarial decentralized coordination. In human subjects experiments, we observe that while adversarial nodes can successfully prevent consensus, the ability to communicate can significantly improve robustness, with the impact particularly significant in scale-free networks. On the other hand, and contrary to typical stylized models of behavior, we show that the existence of trusted nodes has limited utility. Next, we use the data collected in human subject experiments to develop a data-driven agent-based model of adversarial coordination. We show that this model successfully reproduces observed behavior in experiments, is robust to small errors in individual agent models, and illustrate its utility by using it to explore the impact of optimizing network location of trusted and adversarial nodes. 

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3. Keyword expansion techniques for mining social movement data on social media

   https://doi.org/10.1140/epjds/s13688-022-00343-9  

   Bozarth, Lia; Budak, Ceren (May 2022, EPJ Data Science)

   Abstract Political and social scientists have been relying extensively on keywords such as hashtags to mine social movement data from social media sites, particularly Twitter. Yet, prior work demonstrates that unrepresentative keyword sets can lead to flawed research conclusions. Numerous keyword expansion methods have been proposed to increase the comprehensiveness of keywords, but systematic evaluations of these methods have been lacking. Our paper fills this gap. We evaluate five diverse keyword expansion techniques (or pipelines) on five representative social movements across two distinct activity levels. Our results guide researchers who aim to use social media keyword searches to mine data. For instance, we show that word embedding-based methods significantly outperform other even more complex and newer approaches when movements are in normal activity periods. These methods are also less computationally intensive. More importantly, we also observe that no single pipeline can identify little more than half of all movement-related tweets when these movements are at their peak mobilization period offline. However, coverage can increase significantly when more than one pipeline is used. This is true even when the pipelines are selected at random. 

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4. Framing Social Movements on Social Media: Unpacking Diagnostic, Prognostic, and Motivational Strategies

   https://doi.org/10.51685/jqd.2024.icwsm.9  

   Mendelsohn, Julia; Vijan, Maya; Card, Dallas; Budak, Ceren (January 2024, Journal of Quantitative Description: Digital Media)

   Social media enables activists to directly communicate with the public and provides a space for movement leaders, participants, bystanders, and opponents to collectively construct and contest narratives. Focusing on Twitter messages from social movements surrounding three issues in 2018-2019 (guns, immigration, and LGBTQ rights), we create a codebook, annotated dataset, and computational models to detect diagnostic (problem identification and attribution), prognostic (proposed solutions and tactics), and motivational (calls to action) framing strategies. We conduct an in-depth unsupervised linguistic analysis of each framing strategy, and uncover cross-movement similarities in associations between framing and linguistic features such as pronouns and deontic modal verbs. Finally, we compare framing strategies across issues and other social, cultural, and interactional contexts. For example, we show that diagnostic framing is more common in replies than original broadcast posts, and that social movement organizations focus much more on prognostic and motivational framing than journalists and ordinary citizens. 

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5. Assessing Social License to Operate from the Public Discourse on Social Media

   Chang Xu, Ce ́cile (December 2020, Proceedings of the 28th International Conference on Computational Linguistics: Industry Track)

   null (Ed.)

   Organisations are monitoring their Social License to Operate (SLO) with increasing regularity. SLO, the level of support organisations gain from the public, is typically assessed through surveys or focus groups, which require expensive manual efforts and yield quickly-outdated results. In this paper, we present SIRTA (Social Insight via Real-Time Text Analytics), a novel real-time text analytics system for assessing and monitoring organisations’ SLO levels by analysing the public discourse from social posts. To assess SLO levels, our insight is to extract and transform peoples’ stances towards an organisation into SLO levels. SIRTA achieves this by performing a chain of three text classification tasks, where it identifies task-relevant social posts, discovers key SLO risks discussed in the posts, and infers stances specific to the SLO risks. We leverage recent language understanding techniques (e.g., BERT) for building our classifiers. To monitor SLO levels over time, SIRTA employs quality control mechanisms to reliably identify SLO trends and variations of multiple organisations in a market. These are derived from the smoothed time series of their SLO levels based on exponentially-weighted moving average (EWMA) calculation. Our experimental results show that SIRTA is highly effective in distilling stances from social posts for SLO level assessment, and that the continuous monitoring of SLO levels afforded by SIRTA enables the early detection of critical SLO changes. 

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