Research

LLM & NLP
Large Language Models (LLMs) have transformed NLP from task-specific approaches to generalized, data-driven methods, enabling more flexible and intelligent AI applications. Our work enhances LLMs with a multi-agent RAG approach, integrating external, domain-specific data for improved handling of complex, heterogeneous data environments. This improves fairness, transparency, and reliability in LLM-powered applications.
Compound AI Systems
As the emergence of large language models (LLMs) as proficient agents has ushered in a new era of compound AI systems, we address the challenges of building compound AI systems for enterprises. Our systems support agentic workflows in which agents interact with tools and data retrievers to solve complex tasks involving natural language understanding, code generation, and complex reasoning.
Data AI
Symbiosis
Data-AI Symbiosis (DAIS) explores research problems at the intersection of data management and AI. We focus on enterprise data cataloging, fact-checking and verification, data lake usability, and benchmarking multi-agent systems to enable effective knowledge grounding and contextualization for knowledge-guided generation with LLMs. At its core, the DAIS group is working toward building the next-generation data platform that enables self-serving data analytics at scale within compound AI systems involving multi-agent workflows.
Human
Centered AI
We conduct research and development to enable more effective and seamless human-AI collaboration. Our efforts focus on planning for complex tasks while incorporating human feedback, developing conversational interfaces for interacting with compound AI systems, and designing tools and algorithms to enhance data annotation using large language models (LLMs). We aim to redefine how humans and AI systems work together, enabling more intuitive, transparent, and impactful collaborations in complex, real-world contexts.

Compound AI System

The emergence of large language models (LLMs) as proficient agents has ushered in a new era of compound AI systems. We are working toward building a blueprint architecture of compound AI systems tailored for enterprises.

LLM & NLP

We develop techniques and algorithms to advance NLP applications for various complexities and domains through a multi-agent approach across a multi-modal data lake. We also work to improve the functionality of LLMs.

Human-Centered AI

We work on planning for complex tasks while incorporating human feedback. We develop conversational interfaces for interacting with compound AI systems and design tools to enhance data annotation using LLMs.

Data AI Symbiosis

We tackle research problems at the intersection of data management and AI, such as data discovery and natural language query generation, to enable self-serving data exploration and analytics at scale over heterogeneous data management.

Related

Publications

Abstract—Large language models (LLMs) have gained signifi- cant interest in industry due to their impressive capabilities across a wide range of tasks. However, the widespread adoption of LLMs presents several challenges, such as integration into existing ap- plications and infrastructure, utilization of company proprietary data, models, and APIs, and meeting cost, quality, responsiveness, and other requirements. To address these challenges, there is a notable shift from monolithic models to compound AI systems, with the premise of more powerful, versatile, and reliable applications. However, progress thus far has been piecemeal, with proposals for agentic workflows, programming models, and extended LLM capabilities, without a clear vision of an overall architecture. In this paper, we propose a ‘blueprint architecture’ for compound AI systems for orchestrating agents and data for enterprise applications. In our proposed architecture the key orchestration concept is ‘streams’ to coordinate the flow of data and instructions among agents. Existing proprietary models and APIs in the enterprise are mapped to ‘agents’, defined in an ‘agent registry’ that serves agent metadata and learned representations for search and planning. Agents can utilize proprietary data through a ‘data registry’ that similarly registers enterprise data of various modalities. Tying it all together, data and task ‘planners’ break down, map, and optimize tasks and queries for given quality of service (QoS) requirements such as cost, accuracy, and latency. We illustrate an implementation of the architecture for a use-case in the HR domain and discuss opportunities and challenges for ‘agentic AI’ in the enterprise. Index Terms—Agents, Agentic Workflows, LLMs, AI System.
CHI - HEAL Workshop
2025
Yoo Yeon Sung, Hannah Kim, Dan Zhang
AI practitioners increasingly use large language model (LLM) agents in compound AI systems to solve complex reasoning tasks, these agent executions often fail to meet human standards, leading to errors that compromise the system’s overall performance. Addressing these failures through human intervention is challenging due to the agents’ opaque reasoning processes, misalignment with human expectations, the complexity of agent dependencies, and the high cost of manual inspection. This paper thus introduces a human-centered evaluation framework for Verifying LLM Agent failures (VeriLA), which systematically assesses agent failures to reduce human effort and make these agent failures interpretable to humans. The framework first defines clear expectations of each agent by curating human-designed agent criteria. Then, it develops a human-aligned agent verifier module, trained with human gold standards, to assess each agent’s execution output. This approach enables granular evaluation of each agent’s performance by revealing failures from a human standard, offering clear guidelines for revision, and reducing human cognitive load. Our case study results show that VeriLA is both interpretable and efficient in helping practitioners interact more effectively with the system. By upholding accountability in human-agent collaboration, VeriLA paves the way for more trustworthy and human-aligned compound AI systems.
ICLR
2025
The rapid increase in textual information means we need more efficient methods to sift through, organize, and understand it all. While retrieval-augmented generation (RAG) models excel in accessing information from large document collections, they struggle with complex tasks that require aggregation and reasoning over information spanning across multiple documents–what we call holistic reasoning. Long-context language models (LCLMs) have great potential for managing largescale documents, but their holistic reasoning capabilities remain unclear. In this work, we introduce HoloBench, a novel framework that brings database reasoning operations into text-based contexts, making it easier to systematically evaluate how LCLMs handle holistic reasoning across large documents. Our approach adjusts key factors such as context length, information density, distribution of information, and query complexity to evaluate LCLMs comprehensively. Our experiments show that the amount of information in the context has a bigger influence on LCLM performance than the actual context length. Furthermore, the complexity of queries affects performance more than the amount of information, particularly for different types of queries. Interestingly, queries that involve finding maximum or minimum values are easier for LCLMs and are less affected by context length, even though they pose challenges for RAG systems. However, tasks requiring the aggregation of multiple pieces of information show a noticeable drop in accuracy as context length increases. Additionally, we find that while grouping relevant information generally improves performance, the optimal positioning varies across models. Our findings surface both the advancements and the ongoing challenges in achieving a holistic understanding of long contexts. These can guide future developments in LCLMs and set the stage for creating more robust language models for real-world applications.
Github
Corpus
NAACL
2025
Utilizing large language models (LLMs) to rank a set of items has become a common approach in recommendation and retrieval systems. Typically, these systems focus on ordering a substantial number of documents in a monotonic order based on a given query. However, real-world scenarios often present a different challenge: ranking a comparatively smaller set of items, but according to a variety of diverse and occasionally conflicting conditions. In this paper, we define and explore the task of multi-conditional ranking by introducing MCRank, a benchmark tailored for assessing multi-conditional ranking across various item types and conditions. Our analysis of LLMs using MCRank indicates a significant decrease in performance as the number and complexity of items and conditions grow. To overcome this limitation, we propose a novel decomposed reasoning method, consisting of EXtracting and Sorting the conditions, and then Iteratively Ranking the items (EXSIR). Our extensive experiments show that this decomposed reasoning method enhances LLMs’ performance significantly, achieving up to a 14.4% improvement over existing LLMs. We also provide a detailed analysis of LLMs performance across various condition categories, and examine the effectiveness of decomposition step. Furthermore, we compare our method with existing approaches such as Chain-of-Thought and existing ranking models, demonstrating the superiority of our approach and complexity of MCR task. We released our dataset and code.
NAACL - Findings
2025
Although many studies have investigated and reduced hallucinations in large language models (LLMs) for single-document tasks, research on hallucination in multi-document summarization (MDS) tasks remains largely unexplored. Specifically, it is unclear how the challenges arising from handling multiple documents (e.g., repetition and diversity of information) affect models outputs. In this work, we investigate how hallucinations manifest in LLMs when summarizing topic-specific information from multiple documents. Since no benchmarks exist for investigating hallucinations in MDS, we use existing news and conversation datasets, annotated with topic-specific insights, to create two novel multi-document benchmarks. When evaluating 5 LLMs on our benchmarks, we observe that on average, up to 75% of the content in LLM-generated summary is hallucinated, with hallucinations more likely to occur towards the end of the summaries. Moreover, when summarizing non-existent topic-related information, gpt-3.5-turbo and GPT-4o still generate summaries about 79.35% and 44% of the time, raising concerns about their tendency to fabricate content. To understand the characteristics of these hallucinations, we manually evaluate 700+ insights and find that most errors stem from either failing to follow instructions or producing overly generic insights. Motivated by these observations, we investigate the efficacy of simple post-hoc baselines in mitigating hallucinations but find them only moderately effective. Our results underscore the need for more effective approaches to systematically mitigate hallucinations in MDS. We release our dataset and code.
NAACL - Industry
2025
Large Language Models (LLMs) offer the potential to automate hiring by matching job descriptions with candidate resumes, streamlining recruitment processes, and reducing operational costs. However, biases inherent in these models may lead to unfair hiring practices, reinforcing societal prejudices and undermining workplace diversity. This study examines the performance and fairness of LLMs in job-resume matching tasks within the English language and U.S. context. It evaluates how factors such as gender, race, and educational background influence model decisions, providing critical insights into the fairness and reliability of LLMs in HR applications. Our findings indicate that while recent models have reduced biases related to explicit attributes like gender and race, implicit biases concerning educational background remain significant. These results highlight the need for ongoing evaluation and the development of advanced bias mitigation strategies to ensure equitable hiring practices when using LLMs in industry settings.