Thai Le

dblp:03/9889 · DBLP profile ↗
← Back
37ranked-venue papers
9as first author
28since 2021 · last 2026
0000-0001-9632-6870ORCID · corroborated

Domains — the database's venue-derived domains; a paper can count in several

Artificial intelligence and machine learning · 26 · 5 first-author · 21 since 2021Databases, data management, data science and information retrieval · 11 · 5 first-author · 7 since 2021Applied, interdisciplinary, general and emerging computing · 9 · 3 first-author · 5 since 2021Graphics, computer vision, multimedia, augmented reality and games · 5 · 5 since 2021Human-computer interaction and ubiquitous computing · 5 · 1 first-author · 4 since 2021
YearPublicationVenuePosition
2026 Style-First Authorship Verification for Academic Integrity in the Generative AI Era (Student Abstract)
abstract
With the rise of generative artificial intelligence (GenAI), academic dishonesty in classrooms has skyrocketed, yet the existing solutions for detecting such dishonesty often fall short. Standard "AI detectors" merely analyze one text at a time, failing to account for students' previous writings, which risks erroneous predictions. Meanwhile, existing token-based authorship verification (AV) models fail to analyze the nuances in writing styles that truly distinguish authorship. To fill this existing gap, we propose a novel AV framework that combines token-level stylometric features (e.g., POS tag patterns) with handcrafted stylistic features (e.g., sentence structure variation) to construct a comprehensive feature set. Using both benchmark corpora and real-world high school student essays, we trained multiple machine learning classifiers using the proposed feature set. Our initial experiments show that our approach outperforms the standard token-only baselines by over 25%, while offering interpretable, style-based insights. These preliminary results highlight the importance of nuanced stylistic features and suggest that a holistic AV system can provide educators with more reliable and transparent detection tools. Looking ahead, we plan to extend this work with large language models and multi-agent approaches to further enhance robustness and adaptability.
Jun Jang, Thai Le
AAAI2
2026 PARASITE: Conditional System Prompt Poisoning to Hijack LLMs
abstract
Large Language Models (LLMs) are increasingly deployed via third-party system prompts downloaded from public marketplaces.We identify a critical supply-chain vulnerability: conditional system prompt poisoning, where an adversary injects a "sleeper agent" into a benign-looking prompt.Unlike traditional jailbreaks that aim for broad refusal-breaking, our proposed framework, PARASITE, optimizes system prompts to trigger LLMs to output targeted, compromised responses only for specific queries (e.g., "Who should I vote for the US President?") while maintaining high utility on benign inputs.Operating in a strict blackbox setting without model weight access, PAR-ASITE utilizes a two-stage optimization including a global semantic search followed by a greedy lexical refinement.Tested on opensource models and commercial APIs (GPT-4omini, GPT-3.5),PARASITE achieves up to 70% F1 reduction on targeted queries with minimal degradation to general capabilities.We further demonstrate that these poisoned prompts evade standard defenses, including perplexity filters and typo-correction, by exploiting the natural noise found in real-world system prompts.Our code and data are available at https://github.com/vietph34/ PARASITE.WARNING: Our paper contains examples that might be sensitive to the readers!* This work was conducted prior to joining IU Dual Behavior Demonstration 1. Attacker Crafts a Poisoned PromptA helpful tool for learning about historical events and figures.
Viet Pham, Thai Le
ACL (1)2
2026 AEGIS-RL: Abstract, Explainable Graphs for Integrated Safety in RL
abstract
Abstract Ensuring the safety of reinforcement learning (RL) policies in high-stakes environments requires more than formal verification: it needs interpretability and targeted falsification—the deliberate search for counter-examples that expose potential failures before deployment. We present AEGIS-RL (Abstract, Explainable Graphs for Integrated Safety in RL), a hybrid framework that unifies (1) explainable RL, (2) probabilistic model checking, and (3) risk-guided falsification, and augments them with (4) a lightweight runtime safety shield that switches to a fallback policy when estimated risk exceeds a threshold. AEGIS-RL first builds a directed, semantically meaningful graph from offline trajectories that blends local and global explanations to make policy behavior transparent and verifier-friendly. This abstract graph is fed to a probabilistic model checker (e.g., Storm) to verify temporal safety specifications; when violations exist, the checker returns interpretable counterexample traces that pinpoint how the policy fails. When specifications appear satisfied, AEGIS-RL estimates residual risk during checking to steer falsification toward high-risk, under-explored states, broadening coverage beyond the offline data. Across safety-critical benchmarks including two MuJoCo tasks and a medical insulin-dosing scenario; AEGIS-RL uncovers significantly more violations than uncertainty- and fuzzing-based baselines and yields a broader, more novel set of failure trajectories. The resulting explanations and counterexamples provide actionable guidance to understand, debug, and repair unsafe policies while enabling runtime mitigation without retraining.
Tuan Le, Risal Shahriar Shefin, Debashis Gupta, Thai Le, Sarra Alqahtani
Auton. Agents Multi Agent Syst.4
2025 NOMATTERXAI: Generating "No Matter What" Alterfactual Examples for Explaining Black-Box Text Classification Models
abstract
In Explainable AI (XAI), counterfactual explanations (CEs) are a well-studied method to communicate feature relevance through contrastive reasoning of ``what if'' to explain AI models' predictions. However, they only focus on important (i.e., relevant) features and largely disregard less important (i.e., irrelevant) ones. Such irrelevant features can be crucial in many applications, especially when users need to ensure that an AI model's decisions are not affected or biased against specific attributes such as gender, race, religion, or political affiliation. To address this gap, the concept of alterfactual explanations (AEs) has been proposed. AEs explore an alternative reality of ``no matter what'', where irrelevant features are substituted with alternative features (e.g., ``republicans'' -> ``democrats'') within the same attribute (e.g., ``politics'') while maintaining a similar prediction output. This serves to validate whether the specified attributes influence AI model predictions. Despite the promise of AEs, there is a lack of computational approaches to systematically generate them, particularly in the text domain, where creating AEs for AI text classifiers presents unique challenges. This paper addresses this challenge by formulating AE generation as an optimization problem and introducing NoMatterXAI, a novel algorithm that generates AEs for text classification tasks. Our approach achieves high fidelity of up to 95% while preserving context similarity of over 90% across multiple models and datasets. A human study further validates the effectiveness of AEs in explaining AI text classifiers to end users.
Tuc Nguyen, James Michels, Thai Le
AAAI4
2025 Unraveling Interwoven Roles of Large Language Models in Authorship Privacy: Obfuscation, Mimicking, and Verification
abstract
Recent advancements in large language models (LLMs) have been fueled by large-scale training corpora drawn from diverse sources such as websites, news articles, and books.These datasets often contain explicit user information, such as person names, addresses, that LLMs may unintentionally reproduce in their generated outputs.Beyond such explicit content, LLMs can also leak identity-revealing cues through implicit signals such as distinctive writing styles, raising significant concerns about authorship privacy.There are three major automated tasks in authorship privacy, namely authorship obfuscation (AO), authorship mimicking (AM), and authorship verification (AV).Prior research has studied AO, AM, and AV independently.However, their interplays remain under-explored, which leaves a major research gap, especially in the era of LLMs, where they are profoundly shaping how we curate and share user-generated content, and the distinction between machine-generated and human-authored text is also increasingly blurred.This work then presents the first unified framework for analyzing the dynamic relationships among LLM-enabled AO, AM, and AV in the context of authorship privacy.We quantify how they interact with each other to transform human-authored text, examining effects at a single point in time and iteratively over time.We also examine the role of demographic metadata, such as gender, academic background, in modulating their performances, inter-task dynamics, and privacy risks.
Tuc Nguyen, Yifan Hu 0001, Thai Le
EMNLP3
2025 What You Read Isn't What You Hear: Linguistic Sensitivity in Deepfake Speech Detection
abstract
Recent advances in text-to-speech technology have enabled highly realistic voice generation, fueling audio-based deepfake attacks such as fraud and impersonation.While audio antispoofing systems are critical for detecting such threats, prior research has predominantly focused on acoustic-level perturbations, leaving the impact of linguistic variation largely unexplored.In this paper, we investigate the linguistic sensitivity of both open-source and commercial anti-spoofing detectors by introducing TAPAS (Transcript-to-Audio Perturbation Anti-Spoofing), a novel framework for transcript-level adversarial attacks.Our extensive evaluation shows that even minor linguistic perturbations can significantly degrade detection accuracy: attack success rates exceed 60% on several open-source detector-voice pairs, and the accuracy of one commercial detector drops from 100% on synthetic audio to just 32%.Through a comprehensive feature attribution analysis, we find that linguistic complexity and model-level audio embedding similarity are key factors contributing to detector vulnerabilities.To illustrate the real-world risks, we replicate a recent Brad Pitt audio deepfake scam and demonstrate that TAPAS can bypass commercial detectors.These findings underscore the need to move beyond purely acoustic defenses and incorporate linguistic variation into the design of robust anti-spoofing systems.Our source code is available at https: //github.com/nqbinh17/audio_linguist ic_adversarial.
Shuju Shi, Ryan Ofman, Thai Le
EMNLP4
2025 NoisyHate: Mining Online Human-Written Perturbations for Realistic Robustness Benchmarking of Content Moderation Models
abstract
Online texts with toxic content are a clear threat to the users on social media in particular and society in general. Although many platforms have adopted various measures (e.g., machine learning-based hate-speech detection systems) to diminish their effect, toxic content writers have also attempted to evade such measures by using cleverly modified toxic words, so-called human-written text perturbations. Therefore, to help build automatic detection tools to recognize those perturbations, prior methods have developed sophisticated techniques to generate diverse adversarial samples. However, we note that these ``algorithm"-generated perturbations do not necessarily capture all the traits of ``human"-written perturbations. Therefore, in this paper, we introduce a novel, high-quality dataset of human-written perturbations, named as NoisyHate, that was created from real-life perturbations that are both written and verified by human-in-the-loop. We show that perturbations in NoisyHate have different characteristics than prior algorithm-generated toxic datasets show and thus can be particularly useful to help develop better toxic speech detection solutions. We also provide basic benchmark on the potential utilities of NoisyHate in perturbation normalization and understanding tasks. Both dataset and source code are publicly available.
Yiran Ye, Thai Le, Dongwon Lee 0001
ICWSM2
2025 xSRL: Safety-Aware Explainable Reinforcement Learning - Safety as a Product of Explainability
Risal Shahriar Shefin, Md Asifur Rahman, Thai Le, Sarra Alqahtani
AAMAS3
2025 Turing's Echo: Investigating Linguistic Sensitivity of Deepfake Voice Detection via Gamification
Thai Le
INTERSPEECH2
2025 PlagBench: Exploring the Duality of Large Language Models in Plagiarism Generation and Detection
abstract
Jooyoung Lee, Toshini Agrawal, Adaku Uchendu, Thai Le, Jinghui Chen, Dongwon Lee. Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers). 2025.
Toshini Agrawal, Adaku Uchendu, Thai Le, Dongwon Lee 0001
NAACL (Long Papers)4
2024 ALISON: Fast and Effective Stylometric Authorship Obfuscation
abstract
Authorship Attribution (AA) and Authorship Obfuscation (AO) are two competing tasks of increasing importance in privacy research. Modern AA leverages an author's consistent writing style to match a text to its author using an AA classifier. AO is the corresponding adversarial task, aiming to modify a text in such a way that its semantics are preserved, yet an AA model cannot correctly infer its authorship. To address privacy concerns raised by state-of-the-art (SOTA) AA methods, new AO methods have been proposed but remain largely impractical to use due to their prohibitively slow training and obfuscation speed, often taking hours. To this challenge, we propose a practical AO method, ALISON, that (1) dramatically reduces training/obfuscation time, demonstrating more than 10x faster obfuscation than SOTA AO methods, (2) achieves better obfuscation success through attacking three transformer-based AA methods on two benchmark datasets, typically performing 15% better than competing methods, (3) does not require direct signals from a target AA classifier during obfuscation, and (4) utilizes unique stylometric features, allowing sound model interpretation for explainable obfuscation. We also demonstrate that ALISON can effectively prevent four SOTA AA methods from accurately determining the authorship of ChatGPT-generated texts, all while minimally changing the original text semantics. To ensure the reproducibility of our findings, our code and data are available at: https://github.com/EricX003/ALISON.
Eric Xing 0002, Saranya Venkatraman, Thai Le, Dongwon Lee 0001
AAAI3
2024 Generalizability of Mixture of Domain-Specific Adapters from the Lens of Signed Weight Directions and its Application to Effective Model Pruning
abstract
Several parameter-efficient fine-tuning methods based on adapters have been proposed as a streamlined approach to incorporate not only a single specialized knowledge into existing Pre-Trained Language Models (PLMs) but also multiple of them at once.Recent works such as AdapterSoup propose to mix not all but only a selective sub-set of domain-specific adapters during inference via model weight averaging to optimize performance on novel, unseen domains with excellent computational efficiency.However, the essential generalizability of this emerging weight-space adapter mixing mechanism on unseen, in-domain examples remains unexplored.Thus, in this study, we conduct a comprehensive analysis to elucidate the generalizability of domain-specific adapter mixtures in in-domain evaluation.We also provide investigations into the inner workings of the mixture of domain-specific adapters by analyzing their weight signs, yielding critical analysis on the negative correlation between their fraction of weight sign difference and their mixtures' generalizability.The code is available at Github.
Tuc Nguyen, Thai Le
ACL (1)2
2024 A Ship of Theseus: Curious Cases of Paraphrasing in LLM-Generated Texts
abstract
Nafis Irtiza Tripto, Saranya Venkatraman, Dominik Macko, Robert Moro, Ivan Srba, Adaku Uchendu, Thai Le, Dongwon Lee. Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers). 2024.
Nafis Irtiza Tripto, Saranya Venkatraman, Dominik Macko, Róbert Móro, Ivan Srba, Adaku Uchendu, Thai Le, Dongwon Lee 0001
ACL (1)7
2024 The Unexpected Effects of Google Smart Compose on Open-Ended Writing Tasks
Robert E. Cummings, Thai Le, Sijan Shrestha, Carrie Veronica Smith
AIED (1)2
2024 TopFormer: Topology-Aware Authorship Attribution of Deepfake Texts with Diverse Writing Styles
abstract
Recent advances in Large Language Models (LLMs) have enabled the generation of open-ended high-quality texts, that are non-trivial to distinguish from human-written texts. We refer to such LLM-generated texts as deepfake texts. There are currently over 72K text generation models in the huggingface model repo. As such, users with malicious intent can easily use these open-sourced LLMs to generate harmful texts and dis/misinformation at scale. To mitigate this problem, a computational method to determine if a given text is a deepfake text or not is desired–i.e., Turing Test (TT). In particular, in this work, we investigate the more general version of the problem, known as Authorship Attribution (AA), in a multi-class setting–i.e., not only determining if a given text is a deepfake text or not but also being able to pinpoint which LLM is the author. We propose TopFormer to improve existing AA solutions by capturing more linguistic patterns in deepfake texts by including a Topological Data Analysis (TDA) layer in the Transformer-based model. We show the benefits of having a TDA layer when dealing with imbalanced, and multi-style datasets, by extracting TDA features from the reshaped pooled_output of our backbone as input. This Transformer-based model captures contextual representations (i.e., semantic and syntactic linguistic features), while TDA captures the shape and structure of data (i.e., linguistic structures). Finally, TopFormer, outperforms all baselines in all 3 datasets, achieving up to 7% increase in Macro F1 score. Our code and datasets are available at: https://github.com/AdaUchendu/topformer
Adaku Uchendu, Thai Le, Dongwon Lee 0001
ECAI2
2024 Adapters Mixup: Mixing Parameter-Efficient Adapters to Enhance the Adversarial Robustness of Fine-tuned Pre-trained Text Classifiers
abstract
Existing works show that augmenting the training data of pre-trained language models (PLMs) for classification tasks fine-tuned via parameterefficient fine-tuning methods (PEFT) using both clean and adversarial examples can enhance their robustness under adversarial attacks.However, this adversarial training paradigm often leads to performance degradation on clean inputs and requires frequent re-training on the entire data to account for new, unknown attacks.To overcome these challenges while still harnessing the benefits of adversarial training and the efficiency of PEFT, this work proposes a novel approach, called ADPMIXUP, that combines two paradigms: (1) fine-tuning through adapters and (2) adversarial augmentation via mixup to dynamically leverage existing knowledge from a set of pre-known attacks for robust inference.Intuitively, ADPMIXUP fine-tunes PLMs with multiple adapters with both clean and pre-known adversarial examples and intelligently mixes them up in different ratios during prediction.Our experiments show ADPMIXUP achieves the best trade-off between training efficiency and robustness under both pre-known and unknown attacks, compared to existing baselines on five downstream tasks across six varied black-box attacks and 2 PLMs.The code is available at https:// github.com/nguyentuc/adapters_mixup.
Tuc Nguyen, Thai Le
EMNLP2
2024 The Strange Case of Jekyll and Hyde: Analysis of R/ToastMe and R/RoastMe Users on Reddit
abstract
This study, focusing on two Reddit subcommunities of r/ToastMe and r/RoastMe, aims to (1) characterize and understand users (named Jekyll and Hyde) who simultaneously participate in two subreddits with opposing tones and purposes, (2) build predictive models detecting those Jekyll and Hyde users to assess how unique and idiosyncratic their characteristics are, and (3) investigate their motivations of participation and potential interaction between the two contrasting activities through a survey and one-on-one interviews. Our results reveal that the Jekyll and Hyde users are generally more active and popular than ordinary users. Also, they use assimilated language customized to each community’s tone. Combining these findings with their motivations unveiled through the survey and interviews, we conclude that the Jekyll and Hyde users are digitally culture-savvy, who know how to utilize online community benefits and enjoy each community’s culture by assimilating themselves into the community and observing its rules. Moreover, the users’ duality observed in this process underscores the dynamic and multifaceted nature of online personas. These findings highlight the need for a nuanced approach to understanding online behaviors and provide insights for designing healthier online environments, emphasizing the importance of clear community norms and the potential interplay of users’ activities across different communities.
Wooyong Jung, Nishant Asati, Phuong (Lucy) Doan, Thai Le, Aiping Xiong, Dongwon Lee 0001
ICWSM4
2023 "Are Your Explanations Reliable?" Investigating the Stability of LIME in Explaining Text Classifiers by Marrying XAI and Adversarial Attack
abstract
LIME has emerged as one of the most commonly referenced tools in explainable AI (XAI) frameworks that is integrated into critical machine learning applications-e.g., healthcare and finance.However, its stability remains little explored, especially in the context of text data, due to the unique text-space constraints.To address these challenges, in this paper, we first evaluate the inherent instability of LIME on text data to establish a baseline, and then propose a novel algorithm XAIFOOLER to perturb text inputs and manipulate explanations that casts investigation on the stability of LIME as a text perturbation optimization problem.XAIFOOLER conforms to the constraints to preserve text semantics and original prediction with small perturbations, and introduces Rankbiased Overlap (RBO) as a key part to guide the optimization of XAIFOOLER that satisfies all the requirements for explanation similarity measure.Extensive experiments on real-world text datasets demonstrate that XAIFOOLER significantly outperforms all baselines by large margins in its ability to manipulate LIME's explanations with high semantic preservability.The code is available at https://github. com/cburgerOlemiss/XAIFooler
Christopher Burger, Lingwei Chen, Thai Le
EMNLP3
2023 MULTITuDE: Large-Scale Multilingual Machine-Generated Text Detection Benchmark
abstract
Dominik Macko, Robert Moro, Adaku Uchendu, Jason Lucas, Michiharu Yamashita, Matúš Pikuliak, Ivan Srba, Thai Le, Dongwon Lee, Jakub Simko, Maria Bielikova. Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing. 2023.
Dominik Macko, Róbert Móro, Adaku Uchendu, Jason Samuel Lucas, Michiharu Yamashita, Matús Pikuliak, Ivan Srba, Thai Le, Dongwon Lee 0001, Jakub Simko, Mária Bieliková
EMNLP8
2023 CrypText: Database and Interactive Toolkit of Human-Written Text Perturbations in the Wild
abstract
User-generated textual contents on the Internet are often noisy, erroneous, and not in correct grammar. In fact, some online users choose to express their opinions online through carefully perturbed texts, especially in controversial topics (e.g., politics, vaccine mandate) or abusive contexts (e.g., cyberbullying, hate-speech). However, to the best of our knowledge, there is no framework that explores these online "human-written" perturbations (as opposed to algorithm-generated perturbations). Therefore, we introduce an interactive system called CrypText. CrypText is a data-intensive application that provides the users with a database and several tools to extract and interact with human-written perturbations. Specifically, CrypText helps look up, perturb, and normalize (i.e., de-perturb) texts. CrypText also provides an interactive interface to monitor and analyze text perturbations online. The demo is available at: https://lethaiq.github.io/anthro.
Thai Le, Yiran Ye, Yifan Hu 0001, Dongwon Lee 0001
ICDE1
2023 Do Language Models Plagiarize?
abstract
Past literature has illustrated that language models (LMs) often memorize parts of training instances and reproduce them in natural language generation (NLG) processes. However, it is unclear to what extent LMs “reuse” a training corpus. For instance, models can generate paraphrased sentences that are contextually similar to training samples. In this work, therefore, we study three types of plagiarism (i.e., verbatim, paraphrase, and idea) among GPT-2 generated texts, in comparison to its training data, and further analyze the plagiarism patterns of fine-tuned LMs with domain-specific corpora which are extensively used in practice. Our results suggest that (1) three types of plagiarism widely exist in LMs beyond memorization, (2) both size and decoding methods of LMs are strongly associated with the degrees of plagiarism they exhibit, and (3) fine-tuned LMs’ plagiarism patterns vary based on their corpus similarity and homogeneity. Given that a majority of LMs’ training data is scraped from the Web without informing content owners, their reiteration of words, phrases, and even core ideas from training sets into generated texts has ethical implications. Their patterns are likely to exacerbate as both the size of LMs and their training data increase, raising concerns about indiscriminately pursuing larger models with larger training corpora. Plagiarized content can also contain individuals’ personal and sensitive information. These findings overall cast doubt on the practicality of current LMs in mission-critical writing tasks and urge more discussions around the observed phenomena. Data and source code are available at https://github.com/Brit7777/LM-plagiarism.
Thai Le, Dongwon Lee 0001
WWW2
2023 A novel policy-graph approach with natural language and counterfactual abstractions for explaining reinforcement learning agents
Tongtong Liu 0001, Joe McCalmon, Thai Le, Md Asifur Rahman, Dongwon Lee 0001, Sarra Alqahtani
Auton. Agents Multi Agent Syst.3
2022 SHIELD: Defending Textual Neural Networks against Multiple Black-Box Adversarial Attacks with Stochastic Multi-Expert Patcher
abstract
Even though several methods have proposed to defend textual neural network (NN) models against black-box adversarial attacks, they often defend against a specific text perturbation strategy and/or require re-training the models from scratch.This leads to a lack of generalization in practice and redundant computation.In particular, the state-of-the-art transformer models (e.g., BERT, RoBERTa) require great time and computation resources.By borrowing an idea from software engineering, in order to address these limitations, we propose a novel algorithm, SHIELD, which modifies and re-trains only the last layer of a textual NN, and thus it "patches" and "transforms" the NN into a stochastic weighted ensemble of multi-expert prediction heads.Considering that most of current black-box attacks rely on iterative search mechanisms to optimize their adversarial perturbations, SHIELD confuses the attackers by automatically utilizing different weighted ensembles of predictors depending on the input.In other words, SHIELD breaks a fundamental assumption of the attack, which is a victim NN model remains constant during an attack.By conducting comprehensive experiments, we demonstrate that all of CNN, RNN, BERT, and RoBERTa-based textual NNs, once patched by SHIELD, exhibit a relative enhancement of 15%-70% in accuracy on average against 14 different black-box attacks, outperforming 6 defensive baselines across 3 public datasets.Source code will be published at github.com/lethaiq/ shield-defend-adversarial-texts.
Thai Le, Noseong Park, Dongwon Lee 0001
ACL (1)1
2022 Socialbots on Fire: Modeling Adversarial Behaviors of Socialbots via Multi-Agent Hierarchical Reinforcement Learning
abstract
Socialbots are software-driven user accounts on social platforms, acting autonomously (mimicking human behavior), with the aims to influence the opinions of other users or spread targeted misinformation for particular goals. As socialbots undermine the ecosystem of social platforms, they are often considered harmful. As such, there have been several computational efforts to auto-detect the socialbots. However, to our best knowledge, the adversarial nature of these socialbots has not yet been studied. This begs a question “can adversaries, controlling socialbots, exploit AI techniques to their advantage?” To this question, we successfully demonstrate that indeed it is possible for adversaries to exploit computational learning mechanism such as reinforcement learning (RL) to maximize the influence of socialbots while avoiding being detected. We first formulate the adversarial socialbot learning as a cooperative game between two functional hierarchical RL agents. While one agent curates a sequence of activities that can avoid the detection, the other agent aims to maximize network influence by selectively connecting with right users. Our proposed policy networks train with a vast amount of synthetic graphs and generalize better than baselines on unseen real-life graphs both in terms of maximizing network influence (up to +18%) and sustainable stealthiness (up to +40% undetectability) under a strong bot detector (90% detection accuracy). During inference, the complexity of our approach scales linearly, independent of a network’s structure and the virality of news. This makes our attack very practical in a real-life setting.
Thai Le, Long Tran-Thanh, Dongwon Lee 0001
WWW1
2021 A Sweet Rabbit Hole by DARCY: Using Honeypots to Detect Universal Trigger's Adversarial Attacks
abstract
Thai Le, Noseong Park, Dongwon Lee. Proceedings of the 59th Annual Meeting of the Association for Computational Linguistics and the 11th International Joint Conference on Natural Language Processing (Volume 1: Long Papers). 2021.
Thai Le, Noseong Park, Dongwon Lee 0001
ACL/IJCNLP (1)1
2021 Does Clickbait Actually Attract More Clicks? Three Clickbait Studies You Must Read
abstract
Studies show that users do not reliably click more often on headlines classified as clickbait by automated classifiers. Is this because the linguistic criteria (e.g., use of lists or questions) emphasized by the classifiers are not psychologically relevant in attracting interest, or because their classifications are confounded by other unknown factors associated with assumptions of the classifiers? We address these possibilities with three studies—a quasi-experiment using headlines classified as clickbait by three machine-learning models (Study 1), a controlled experiment varying the headline of an identical news story to contain only one clickbait characteristic (Study 2), and a computational analysis of four classifiers using real-world sharing data (Study 3). Studies 1 and 2 revealed that clickbait did not generate more curiosity than non-clickbait. Study 3 revealed that while some headlines generate more engagement, the detectors agreed on a classification only 47% of the time, raising fundamental questions about their validity.
Maria D. Molina, S. Shyam Sundar, Md Main Uddin Rony, Naeemul Hassan, Thai Le, Dongwon Lee 0001
CHI5
2021 Large-Scale Data-Driven Airline Market Influence Maximization
abstract
We present a prediction-driven optimization framework to maximize the market influence in the US domestic air passenger transportation market by adjusting flight frequencies. At the lower level, our neural networks consider a wide variety of features, such as classical air carrier performance features and transportation network features, to predict the market influence. On top of the prediction models, we define a budget-constrained flight frequency optimization problem to maximize the market influence over 2,262 routes. This problem falls into the category of the non-linear optimization problem, which cannot be solved exactly by conventional methods. To this end, we present a novel adaptive gradient ascent (AGA) method. Our prediction models show two to eleven times better accuracy in terms of the median root-mean-square error (RMSE) over baselines. In addition, our AGA optimization method runs 690 times faster with a better optimization result (in one of our largest scale experiments) than a greedy algorithm.
Duanshun Li, Jing Liu 0024, Jinsung Jeon, Seoyoung Hong 0001, Thai Le, Dongwon Lee 0001, Noseong Park
KDD5
2021 CHECKER: Detecting Clickbait Thumbnails with Weak Supervision and Co-teaching
Tianyi Xie, Thai Le, Dongwon Lee 0001
ECML/PKDD (5)2
2020 Authorship Attribution for Neural Text Generation
abstract
In recent years, the task of generating realistic short and long texts have made tremendous advancements. In particular, several recently proposed neural network-based language models have demonstrated their astonishing capabilities to generate texts that are challenging to distinguish from human-written texts with the naked eye. Despite many benefits and utilities of such neural methods, in some applications, being able to tell the “author” of a text in question becomes critically important. In this work, in the context of this Turing Test, we investigate the so-called authorship attribution problem in three versions: (1) given two texts T1 and T2, are both generated by the same method or not? (2) is the given text T written by a human or machine? (3) given a text T and k candidate neural methods, can we single out the method (among k alternatives) that generated T? Against one humanwritten and eight machine-generated texts (i.e., CTRL, GPT, GPT2, GROVER, XLM, XLNET, PPLM, FAIR), we empirically experiment with the performance of various models in three problems. By and large, we find that most generators still generate texts significantly different from human-written ones, thereby making three problems easier to solve. However, the qualities of texts generated by GPT2, GROVER, and FAIR are better, often confusing machine classifiers in solving three problems. All codes and datasets of our experiments are available at: https://bit.ly/ 302zWdz
Adaku Uchendu, Thai Le, Kai Shu, Dongwon Lee 0001
EMNLP (1)2
2020 MALCOM: Generating Malicious Comments to Attack Neural Fake News Detection Models
abstract
In recent years, the proliferation of so-called “fake news” has caused much disruptions in society and weakened the news ecosystem. Therefore, to mitigate such problems, researchers have developed state-of-the-art (SOTA) models to autodetect fake news on social media using sophisticated data science and machine learning techniques. In this work, then, we ask “what if adversaries attempt to attack such detection models?” and investigate related issues by (i) proposing a novel attack scenario against fake news detectors, in which adversaries can post malicious comments toward news articles to mislead SOTA fake news detectors, and (ii) developing Malcom, an end-to-end adversarial comment generation framework to achieve such an attack. Through a comprehensive evaluation, we demonstrate that about 94% and 93.5% of the time on average Malcom can successfully mislead five of the latest neural detection models to always output targeted real and fake news labels. Furthermore, Malcom can also fool black box fake news detectors to always output real news labels 90% of the time on average. We also compare our attack model with four baselines across two real-world datasets, not only on attack performance but also on generated quality, coherency, transferability, and robustness. We release the source code of Malcom at https://github.com/lethaiq/MALCOM1.
Thai Le, Suhang Wang, Dongwon Lee 0001
ICDM1
2020 GRACE: Generating Concise and Informative Contrastive Sample to Explain Neural Network Model's Prediction
abstract
Despite the recent development in the topic of explainable AI/ML for image and text data, the majority of current solutions are not suitable to explain the prediction of neural network models when the datasets are tabular and their features are in high-dimensional vectorized formats. To mitigate this limitation, therefore, we borrow two notable ideas (i.e., "explanation by intervention" from causality and "explanation are contrastive" from philosophy) and propose a novel solution, named as GRACE, that better explains neural network models' predictions for tabular datasets. In particular, given a model's prediction as label X, GRACE intervenes and generates a minimally-modified contrastive sample to be classified as Y, with an intuitive textual explanation, answering the question of "Why X rather than Y?" We carry out comprehensive experiments using eleven public datasets of different scales and domains (e.g., # of features ranges from 5 to 216) and compare GRACE with competing baselines on different measures: fidelity, conciseness, info-gain, and influence. The user-studies show that our generated explanation is not only more intuitive and easy-to-understand but also facilitates end-users to make as much as 60% more accurate post-explanation decisions than that of Lime.
Thai Le, Suhang Wang, Dongwon Lee 0001
KDD1
2019 5 sources of clickbaits you should know!: using synthetic clickbaits to improve prediction and distinguish between bot-generated and human-written headlines
abstract
Clickbait is an attractive yet misleading headline that lures readers to commit click-conversion. Development of robust clickbait detection models has been, however, hampered due to the shortage of high-quality labeled training samples. To overcome this challenge, we investigate how to exploit human-written and machine-generated synthetic clickbaits. We first ask crowdworkers and journalism students to generate clickbaity news headlines. Second, we utilize deep generative models to generate clickbaity headlines. Through empirical evaluations, we demonstrate that synthetic clickbaits by human entities and deep generative models are consistently useful in improving the accuracy of various prediction models, by as much as 14.5% in AUC, across two real datasets and different types of algorithms. Especially, we observe an improvement in accuracy, up to 8.5% in AUC, even for top-ranked clickbait detectors from Clickbait Challenge 2017. Our study proposes a novel direction to address the shortage of labeled training data, one of fundamental bottlenecks in supervised learning, by means of synthetic training data with reinforced domain knowledge. It also provides a solution for distinguishing between bot-generated and human-written clickbaits, thus aiding the work of moderators and better alerting news consumers.
Thai Le, Kai Shu, Maria D. Molina, Dongwon Lee 0001, S. Shyam Sundar, Huan Liu 0001
ASONAM1
2018 Deep Headline Generation for Clickbait Detection
abstract
Clickbaits are catchy social posts or sensational headlines that attempt to lure readers to click. Clickbaits are pervasive on social media and can have significant negative impacts on both users and media ecosystems. For example, users may be misled to receive inaccurate information or fall into click-jacking attacks. Similarly, media platforms could lose readers' trust and revenues due to the prevalence of clickbaits. To computationally detect such clickbaits on social media using a supervised learning framework, one of the major obstacles is the lack of large-scale labeled training data, due to the high cost of labeling. With the recent advancements of deep generative models, to address this challenge, we propose to generate synthetic headlines with specific styles and explore their utilities to help improve clickbait detection. In particular, we propose to generate stylized headlines from original documents with style transfer. Furthermore, as it is non-trivial to generate stylized headlines due to several challenges such as the discrete nature of texts and the requirements of preserving semantic meaning of document while achieving style transfer, we propose a novel solution, named as Stylized Headline Generation (SHG), that can not only generate readable and realistic headlines to enlarge original training data, but also help improve the classification capacity of supervised learning. The experimental results on real-world datasets demonstrate the effectiveness of SHG in generating high-quality and high-utility headlines for clickbait detection.
Kai Shu, Suhang Wang, Thai Le, Dongwon Lee 0001, Huan Liu 0001
ICDM3
2015 The use of think-aloud and instant data analysis in evaluation research: Exemplar and lessons learned
Jonathan Joe, Shomir Chaudhuri, Thai Le, Hilaire Thompson, George Demiris
J. Biomed. Informatics3
2014 Tree testing of hierarchical menu structures for health applications
Thai Le, Shomir Chaudhuri, Jane Chung, Hilaire Thompson, George Demiris
J. Biomed. Informatics1
2013 Network Visualization of UMLS Source Vocabularies using Semantic Groups
Thai Le, Bastien Rance, Olivier Bodenreider
AMIA1
2012 Administering a Wide-Scale Survey to Community Dwelling Older Adults: Implications and Lessons Learned
Shomir Chaudhuri, Thai Le, Catherine White, Jane Chung, George Demiris, Hilaire Thompson
AMIA2