Lingbo Mo


2024

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How Trustworthy are Open-Source LLMs? An Assessment under Malicious Demonstrations Shows their Vulnerabilities
Lingbo Mo | Boshi Wang | Muhao Chen | Huan Sun
Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)

The rapid progress in open-source Large Language Models (LLMs) is significantly driving AI development forward. However, there is still a limited understanding of their trustworthiness. Deploying these models at scale without sufficient trustworthiness can pose significant risks, highlighting the need to uncover these issues promptly. In this work, we conduct an adversarial assessment of open-source LLMs on trustworthiness, scrutinizing them across eight different aspects including toxicity, stereotypes, ethics, hallucination, fairness, sycophancy, privacy, and robustness against adversarial demonstrations. We propose advCoU, an extended Chain of Utterances-based (CoU) prompting strategy by incorporating carefully crafted malicious demonstrations for trustworthiness attack. Our extensive experiments encompass recent and representative series of open-source LLMs, including Vicuna, MPT, Falcon, Mistral, and Llama 2. The empirical outcomes underscore the efficacy of our attack strategy across diverse aspects. More interestingly, our result analysis reveals that models with superior performance in general NLP tasks do not always have greater trustworthiness; in fact, larger models can be more vulnerable to attacks. Additionally, models that have undergone instruction tuning, focusing on instruction following, tend to be more susceptible, although fine-tuning LLMs for safety alignment proves effective in mitigating adversarial trustworthiness attacks.

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A Multi-Aspect Framework for Counter Narrative Evaluation using Large Language Models
Jaylen Jones | Lingbo Mo | Eric Fosler-Lussier | Huan Sun
Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 2: Short Papers)

Counter narratives - informed responses to hate speech contexts designed to refute hateful claims and de-escalate encounters - have emerged as an effective hate speech intervention strategy. While previous work has proposed automatic counter narrative generation methods to aid manual interventions, the evaluation of these approaches remains underdeveloped. Previous automatic metrics for counter narrative evaluation lack alignment with human judgment as they rely on superficial reference comparisons instead of incorporating key aspects of counter narrative quality as evaluation criteria. To address prior evaluation limitations, we propose a novel evaluation framework prompting LLMs to provide scores and feedback for generated counter narrative candidates using 5 defined aspects derived from guidelines from counter narrative specialized NGOs. We found that LLM evaluators achieve strong alignment to human-annotated scores and feedback and outperform alternative metrics, indicating their potential as multi-aspect, reference-free and interpretable evaluators for counter narrative evaluation.

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Insights of a Usability Study for KBQA Interactive Semantic Parsing: Generation Yields Benefits over Templates but External Validity Remains Challenging
Ashley Lewis | Lingbo Mo | Marie-Catherine de Marneffe | Huan Sun | Michael White
Proceedings of the Fourth Workshop on Human Evaluation of NLP Systems (HumEval) @ LREC-COLING 2024

We present our findings from a usability study of an interactive semantic parsing system for knowledge based question answering (KBQA). The system is designed to help users access information within a knowledge base without having to know its query language. The system translates the user’s question into the query language, retrieves an answer, then presents an English explanation of the process so that the user can make corrections if necessary. To our knowledge, our work is the most thorough usability study conducted for such a system and the only one that uses crowdworkers as participants to verify that the system is usable for average users. Our crowdworkers participate in KBQA dialogues using 4 versions of a system based on the framework by Mo et al. (2022) and answer surveys about their experiences. Some key takeaways from this work are: 1) we provide evidence for the benefits of interactivity in semantic parsing with human users and using generated questions in lieu of templated representations, 2) we identify limitations of simulations and provide contrasting evidence from actual system use, and 3) we provide an examination of crowdsourcing methodology, in particular the trade-offs of using crowdworkers vs. a specially trained group of evaluators.

2023

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Roll Up Your Sleeves: Working with a Collaborative and Engaging Task-Oriented Dialogue System
Lingbo Mo | Shijie Chen | Ziru Chen | Xiang Deng | Ashley Lewis | Sunit Singh | Samuel Stevens | Chang-You Tai | Zhen Wang | Xiang Yue | Tianshu Zhang | Yu Su | Huan Sun
Proceedings of the 24th Annual Meeting of the Special Interest Group on Discourse and Dialogue

We introduce TacoBot, a user-centered task-oriented digital assistant designed to guide users through complex real-world tasks with multiple steps. Covering a wide range of cooking and how-to tasks, we aim to deliver a collaborative and engaging dialogue experience. Equipped with language understanding, dialogue management, and response generation components supported by a robust search engine, TacoBot ensures efficient task assistance. To enhance the dialogue experience, we explore a series of data augmentation strategies using LLMs to train advanced neural models continuously. TacoBot builds upon our successful participation in the inaugural Alexa Prize TaskBot Challenge, where our team secured third place among ten competing teams. We offer TacoBot as an open-source framework that serves as a practical example for deploying task-oriented dialogue systems.

2022

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Towards Transparent Interactive Semantic Parsing via Step-by-Step Correction
Lingbo Mo | Ashley Lewis | Huan Sun | Michael White
Findings of the Association for Computational Linguistics: ACL 2022

Existing studies on semantic parsing focus on mapping a natural-language utterance to a logical form (LF) in one turn. However, because natural language may contain ambiguity and variability, this is a difficult challenge. In this work, we investigate an interactive semantic parsing framework that explains the predicted LF step by step in natural language and enables the user to make corrections through natural-language feedback for individual steps. We focus on question answering over knowledge bases (KBQA) as an instantiation of our framework, aiming to increase the transparency of the parsing process and help the user trust the final answer. We construct INSPIRED, a crowdsourced dialogue dataset derived from the ComplexWebQuestions dataset. Our experiments show that this framework has the potential to greatly improve overall parse accuracy. Furthermore, we develop a pipeline for dialogue simulation to evaluate our framework w.r.t. a variety of state-of-the-art KBQA models without further crowdsourcing effort. The results demonstrate that our framework promises to be effective across such models.

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Knowledge Transfer between Structured and Unstructured Sources for Complex Question Answering
Lingbo Mo | Zhen Wang | Jie Zhao | Huan Sun
Proceedings of the Workshop on Structured and Unstructured Knowledge Integration (SUKI)

Multi-hop question answering (QA) combines multiple pieces of evidence to search for the correct answer. Reasoning over a text corpus (TextQA) and/or a knowledge base (KBQA) has been extensively studied and led to distinct system architectures. However, knowledge transfer between such two QA systems has been under-explored. Research questions like what knowledge is transferred or whether the transferred knowledge can help answer over one source using another one, are yet to be answered. In this paper, therefore, we study the knowledge transfer of multi-hop reasoning between structured and unstructured sources. We first propose a unified QA framework named SimultQA to enable knowledge transfer and bridge the distinct supervisions from KB and text sources. Then, we conduct extensive analyses to explore how knowledge is transferred by leveraging the pre-training and fine-tuning paradigm. We focus on the low-resource fine-tuning to show that pre-training SimultQA on one source can substantially improve its performance on the other source. More fine-grained analyses on transfer behaviors reveal the types of transferred knowledge and transfer patterns. We conclude with insights into how to construct better QA datasets and systems to exploit knowledge transfer for future work.