Xu, Weijie
Strategic resource allocation in memory encoding: An efficiency principle shaping language processing
Xu, Weijie, Futrell, Richard
How is the limited capacity of working memory efficiently used to support human linguistic behaviors? In this paper, we investigate strategic resource allocation as an efficiency principle for memory encoding in sentence processing. The idea is that working memory resources are dynamically and strategically allocated to prioritize novel and unexpected information, enhancing their representations to make them less susceptible to memory decay and interference. Theoretically, from a resource-rational perspective, we argue that this efficiency principle naturally arises from two functional assumptions about working memory, namely, its limited capacity and its noisy representation. Empirically, through naturalistic corpus data, we find converging evidence for strategic resource allocation in the context of dependency locality from both the production and the comprehension side, where non-local dependencies with less predictable antecedents are associated with reduced locality effect. However, our results also reveal considerable cross-linguistic variability, highlighting the need for a closer examination of how strategic resource allocation, as a universal efficiency principle, interacts with language-specific phrase structures.
Neural Topic Modeling with Large Language Models in the Loop
Yang, Xiaohao, Zhao, He, Xu, Weijie, Qi, Yuanyuan, Lu, Jueqing, Phung, Dinh, Du, Lan
Topic modeling is a fundamental task in natural language processing, allowing the discovery of latent thematic structures in text corpora. While Large Language Models (LLMs) have demonstrated promising capabilities in topic discovery, their direct application to topic modeling suffers from issues such as incomplete topic coverage, misalignment of topics, and inefficiency. To address these limitations, we propose LLM-ITL, a novel LLM-in-the-loop framework that integrates LLMs with Neural Topic Models (NTMs). In LLM-ITL, global topics and document representations are learned through the NTM. Meanwhile, an LLM refines these topics using an Optimal Transport (OT)-based alignment objective, where the refinement is dynamically adjusted based on the LLM's confidence in suggesting topical words for each set of input words. With the flexibility of being integrated into many existing NTMs, the proposed approach enhances the interpretability of topics while preserving the efficiency of NTMs in learning topics and document representations. Extensive experiments demonstrate that LLM-ITL helps NTMs significantly improve their topic interpretability while maintaining the quality of document representation. Our code and datasets will be available at Github.
HR-Agent: A Task-Oriented Dialogue (TOD) LLM Agent Tailored for HR Applications
Xu, Weijie, Desai, Jay, Wu, Fanyou, Valvoda, Josef, Sengamedu, Srinivasan H.
Recent LLM (Large Language Models) advancements benefit many fields such as education and finance, but HR has hundreds of repetitive processes, such as access requests, medical claim filing and time-off submissions, which are unaddressed. We relate these tasks to the LLM agent, which has addressed tasks such as writing assisting and customer support. We present HR-Agent, an efficient, confidential, and HR-specific LLM-based task-oriented dialogue system tailored for automating repetitive HR processes such as medical claims and access requests. Since conversation data is not sent to an LLM during inference, it preserves confidentiality required in HR-related tasks.
Mitigating Selection Bias with Node Pruning and Auxiliary Options
Choi, Hyeong Kyu, Xu, Weijie, Xue, Chi, Eckman, Stephanie, Reddy, Chandan K.
To mitigate this selection bias problem, previous solutions utilized debiasing methods to adjust the model's input and/or output. Our work, in contrast, investigates the model's internal representation of the selection bias. Specifically, we introduce a novel debiasing approach, Bias Node Pruning (BNP), which eliminates the linear layer parameters that contribute to the bias. Furthermore, we present Auxiliary Option Injection (AOI), a simple yet effective input modification technique for debiasing, which is compatible even with black-box LLMs. To provide a more systematic evaluation of selection bias, we review existing metrics and introduce Choice Kullback-Leibler Divergence (CKLD), which addresses the insensitivity of the commonly used metrics to imbalance in choice labels. Experiments show that our methods are robust and adaptable across various datasets when applied to three LLMs. The advent of large language models (LLMs) has revolutionized artificial intelligence applications, particularly in the domain of natural language processing. These models have demonstrated outstanding performance across a variety of use cases, including chatbots, machine translation, text generation, data annotation, etc. Their ability to answer questions with high precision has opened up new avenues for automated systems. Despite their remarkable abilities, LLMs suffer from the selection bias problem that often occurs in answering multiplechoice questions (MCQs). When selecting the answer for an MCQ, many LLMs prefer the choices in a given position (e.g., the last choice), or with a specific choice symbol (e.g., (A) or (3)) (Zheng et al., 2024; Wei et al., 2024; Pezeshkpour & Hruschka, 2024). Many previous works have attempted to explain this phenomenon and/or propose diverse ways to mitigate selection bias. While there are a few works focused on either modifying the input format (Li et al., 2023b; Robinson et al., 2023) or calibrating the output probabilities (Zheng et al., 2024; Reif Figure 1: We propose BNP and & Schwartz, 2024; Wei et al., 2024), to the best of our knowledge, AOI to reduce selection bias for no embedding or parameter-level investigation has been white-box and black-box models. Because selection bias originates from internal The CKLD metric is also proposed parameter-level computations, it is crucial to explore how the to encourage a more standardized LLM embeddings contribute to the bias in their output responses. Understanding the internal representation of selection bias can help us combat it. By scrutinizing the interaction between the internal representation and the LLM parameters, we develop a novel approach to debias the model. Specifically, we propose Bias Node Pruning (BNP), which eliminates nodes in the final linear layer that contribute to selection bias. By dropping as few as 32 out of 4096 nodes in the final layer, we can significantly reduce selection bias and improve question-answering performance.
Large Language Models(LLMs) on Tabular Data: Prediction, Generation, and Understanding -- A Survey
Fang, Xi, Xu, Weijie, Tan, Fiona Anting, Zhang, Jiani, Hu, Ziqing, Qi, Yanjun, Nickleach, Scott, Socolinsky, Diego, Sengamedu, Srinivasan, Faloutsos, Christos
Recent breakthroughs in large language modeling have facilitated rigorous exploration of their application in diverse tasks related to tabular data modeling, such as prediction, tabular data synthesis, question answering, and table understanding. Each task presents unique challenges and opportunities. However, there is currently a lack of comprehensive review that summarizes and compares the key techniques, metrics, datasets, models, and optimization approaches in this research domain. This survey aims to address this gap by consolidating recent progress in these areas, offering a thorough survey and taxonomy of the datasets, metrics, and methodologies utilized. It identifies strengths, limitations, unexplored territories, and gaps in the existing literature, while providing some insights for future research directions in this vital and rapidly evolving field. It also provides relevant code and datasets references. Through this comprehensive review, we hope to provide interested readers with pertinent references and insightful perspectives, empowering them with the necessary tools and knowledge to effectively navigate and address the prevailing challenges in the field.
Synthesizing Conversations from Unlabeled Documents using Automatic Response Segmentation
Wu, Fanyou, Xu, Weijie, Reddy, Chandan K., Sengamedu, Srinivasan H.
In this study, we tackle the challenge of inadequate and costly training data that has hindered the development of conversational question answering (ConvQA) systems. Enterprises have a large corpus of diverse internal documents. Instead of relying on a searching engine, a more compelling approach for people to comprehend these documents is to create a dialogue system. In this paper, we propose a robust dialog synthesising method. We learn the segmentation of data for the dialog task instead of using segmenting at sentence boundaries. The synthetic dataset generated by our proposed method achieves superior quality when compared to WikiDialog, as assessed through machine and human evaluations. By employing our inpainted data for ConvQA retrieval system pre-training, we observed a notable improvement in performance across OR-QuAC benchmarks.
A hierarchical Bayesian model for syntactic priming
Xu, Weijie, Futrell, Richard
The effect of syntactic priming exhibits three well-documented empirical properties: the lexical boost, the inverse frequency effect, and the asymmetrical decay. We aim to show how these three empirical phenomena can be reconciled in a general learning framework, the hierarchical Bayesian model (HBM). The model represents syntactic knowledge in a hierarchical structure of syntactic statistics, where a lower level represents the verb-specific biases of syntactic decisions, and a higher level represents the abstract bias as an aggregation of verb-specific biases. This knowledge is updated in response to experience by Bayesian inference. In simulations, we show that the HBM captures the above-mentioned properties of syntactic priming. The results indicate that some properties of priming which are usually explained by a residual activation account can also be explained by an implicit learning account. We also discuss the model's implications for the lexical basis of syntactic priming.
PHAnToM: Personality Has An Effect on Theory-of-Mind Reasoning in Large Language Models
Tan, Fiona Anting, Yeo, Gerard Christopher, Wu, Fanyou, Xu, Weijie, Jain, Vinija, Chadha, Aman, Jaidka, Kokil, Liu, Yang, Ng, See-Kiong
Recent advances in large language models (LLMs) demonstrate that their capabilities are comparable, or even superior, to humans in many tasks in natural language processing. Despite this progress, LLMs are still inadequate at social-cognitive reasoning, which humans are naturally good at. Drawing inspiration from psychological research on the links between certain personality traits and Theory-of-Mind (ToM) reasoning, and from prompt engineering research on the hyper-sensitivity of prompts in affecting LLMs capabilities, this study investigates how inducing personalities in LLMs using prompts affects their ToM reasoning capabilities. Our findings show that certain induced personalities can significantly affect the LLMs' reasoning capabilities in three different ToM tasks. In particular, traits from the Dark Triad have a larger variable effect on LLMs like GPT-3.5, Llama 2, and Mistral across the different ToM tasks. We find that LLMs that exhibit a higher variance across personality prompts in ToM also tends to be more controllable in personality tests: personality traits in LLMs like Figure 1: Overview of PHAnToM. Our work investigates GPT-3.5, Llama 2 and Mistral can be controllably how eight different personality prompts (Big Five adjusted through our personality prompts. OCEAN and Dark Triad) affects LLMs' ability to perform In today's landscape where role-play is a common three theory-of-mind reasoning tasks (Information strategy when using LLMs, our research Access (IA), Answerability (AA), and Belief Understanding highlights the need for caution, as models that (BU)).
HR-MultiWOZ: A Task Oriented Dialogue (TOD) Dataset for HR LLM Agent
Xu, Weijie, Huang, Zicheng, Hu, Wenxiang, Fang, Xi, Cherukuri, Rajesh Kumar, Nayyar, Naumaan, Malandri, Lorenzo, Sengamedu, Srinivasan H.
Recent advancements in Large Language Models (LLMs) have been reshaping Natural Language Processing (NLP) task in several domains. Their use in the field of Human Resources (HR) has still room for expansions and could be beneficial for several time consuming tasks. Examples such as time-off submissions, medical claims filing, and access requests are noteworthy, but they are by no means the sole instances. However, the aforementioned developments must grapple with the pivotal challenge of constructing a high-quality training dataset. On one hand, most conversation datasets are solving problems for customers not employees. On the other hand, gathering conversations with HR could raise privacy concerns. To solve it, we introduce HR-Multiwoz, a fully-labeled dataset of 550 conversations spanning 10 HR domains to evaluate LLM Agent. Our work has the following contributions: (1) It is the first labeled open-sourced conversation dataset in the HR domain for NLP research. (2) It provides a detailed recipe for the data generation procedure along with data analysis and human evaluations. The data generation pipeline is transferable and can be easily adapted for labeled conversation data generation in other domains. (3) The proposed data-collection pipeline is mostly based on LLMs with minimal human involvement for annotation, which is time and cost-efficient.
DeTiME: Diffusion-Enhanced Topic Modeling using Encoder-decoder based LLM
Xu, Weijie, Hu, Wenxiang, Wu, Fanyou, Sengamedu, Srinivasan
In the burgeoning field of natural language processing (NLP), Neural Topic Models (NTMs) , Large Language Models (LLMs) and Diffusion model have emerged as areas of significant research interest. Despite this, NTMs primarily utilize contextual embeddings from LLMs, which are not optimal for clustering or capable for topic based text generation. NTMs have never been combined with diffusion model for text generation. Our study addresses these gaps by introducing a novel framework named Diffusion-Enhanced Topic Modeling using Encoder-Decoder-based LLMs (DeTiME). DeTiME leverages Encoder-Decoder-based LLMs to produce highly clusterable embeddings that could generate topics that exhibit both superior clusterability and enhanced semantic coherence compared to existing methods. Additionally, by exploiting the power of diffusion model, our framework also provides the capability to do topic based text generation. This dual functionality allows users to efficiently produce highly clustered topics and topic based text generation simultaneously. DeTiME's potential extends to generating clustered embeddings as well. Notably, our proposed framework(both encoder-decoder based LLM and diffusion model) proves to be efficient to train and exhibits high adaptability to other LLMs and diffusion model, demonstrating its potential for a wide array of applications.