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Xingchen Wan

22 accepted papers

2026

Can Large Language Models Generalize Procedures Across Representations?

ICML 2026poster

Large language models (LLMs) are trained and tested extensively on symbolic representations such as code and graphs, yet real-world user tasks are often specified in natural language. To what extent can LLMs generalize across these representations? Here, we approach this question by studying isomorp…

Cited by 0SourceScholar
2026

Multi-Agent Design: Optimizing Agents with Better Prompts and Topologies

ICLR 2026poster

Large language models, employed as multiple agents that interact and collaborate with each other, have excelled at solving complex tasks. The agents are programmed with prompts that declare their functionality, along with the topologies that orchestrate interactions across agents. Designing prompts…

Cited by 0SourceScholar
2026

VISTA: A Test-Time Self-Improving Video Generation Agent

CVPR 2026

Despite rapid advances in text-to-video synthesis, generated video quality remains critically dependent on precise user prompts. Existing test-time optimization methods, successful in other domains, struggle with the multi-faceted nature of video. In this work, we introduce VISTA (Video Iterative Se

Cited by 0SourcecodeScholar
2026

Visual Planning: Let's Think Only with Images

ICLR 2026oral

Recent advancements in Large Language Models (LLMs) and their multimodal extensions (MLLMs) have substantially enhanced machine reasoning across diverse tasks. However, these models predominantly rely on pure text as the medium for both expressing and structuring reasoning, even when visual informat…

Cited by 0SourcecodeScholar
2025

Astute RAG: Overcoming Imperfect Retrieval Augmentation and Knowledge Conflicts for Large Language Models

ACL 2025long

Retrieval augmented generation (RAG), while effectively integrating external knowledge to address the inherent limitations of large language models (LLMs), can be hindered by imperfect retrieval that contain irrelevant, misleading, or even malicious information. Previous studies have rarely connecte…

Cited by 0SourcePDFScholar
2025

From Few to Many: Self-Improving Many-Shot Reasoners Through Iterative Optimization and Generation

ICLR 2025poster

Recent advances in long-context large language models (LLMs) have led to the emerging paradigm of many-shot in-context learning (ICL), where it is observed that scaling many more demonstrating examples beyond the conventional few-shot setup in the context can lead to performance benefits. However, d…

Cited by 2SourcePDFScholar
2024

Adaptive Batch Sizes for Active Learning: A Probabilistic Numerics Approach

AISTATS 2024poster

Active learning parallelization is widely used, but typically relies on fixing the batch size throughout experimentation. This fixed approach is inefficient because of a dynamic trade-off between cost and speed—larger batches are more costly, smaller batches lead to slower wall-clock run-times—and t…

2024

Batch Calibration: Rethinking Calibration for In-Context Learning and Prompt Engineering

ICLR 2024poster

Prompting and in-context learning (ICL) have become efficient learning paradigms for large language models (LLMs). However, LLMs suffer from prompt brittleness and various bias factors in the prompt, including but not limited to the formatting, the choice verbalizers, and the ICL examples. To addres…

Cited by 51SourcePDFScholar
2024

Bayesian Optimization of Functions over Node Subsets in Graphs

NeurIPS 2024poster

We address the problem of optimizing over functions defined on node subsets in a graph. The optimization of such functions is often a non-trivial task given their combinatorial, black-box and expensive-to-evaluate nature. Although various algorithms have been introduced in the literature, most are…

2024

Fairer Preferences Elicit Improved Human-Aligned Large Language Model Judgments

EMNLP 2024main

Large language models (LLMs) have shown promising abilities as cost-effective and reference-free evaluators for assessing language generation quality. In particular, pairwise LLM evaluators, which compare two generated texts and determine the preferred one, have been employed in a wide range of appl…

2024

Teach Better or Show Smarter? On Instructions and Exemplars in Automatic Prompt Optimization

NeurIPS 2024poster

Large language models have demonstrated remarkable capabilities but their performance is heavily reliant on effective prompt engineering. Automatic prompt optimization (APO) methods are designed to automate this and can be broadly categorized into those targeting instructions (instruction optimizati…

Cited by 13SourcePDFScholar
2024

UQE: A Query Engine for Unstructured Databases

NeurIPS 2024poster

Analytics on structured data is a mature field with many successful methods. However, most real world data exists in unstructured form, such as images and conversations. We investigate the potential of Large Language Models (LLMs) to enable unstructured data analytics. In particular, we propose a ne…

Cited by 1SourcePDFScholar
2023

Bayesian Optimisation of Functions on Graphs

NeurIPS 2023poster

The increasing availability of graph-structured data motivates the task of optimising over functions defined on the node set of graphs. Traditional graph search algorithms can be applied in this case, but they may be sample-inefficient and do not make use of information about the function values; on…

Cited by 5SourcePDFScholar
2023

Better Zero-Shot Reasoning with Self-Adaptive Prompting

ACL 2023findings

Modern large language models (LLMs) have demonstrated impressive capabilities at sophisticated tasks, often through step-by-step reasoning similar to humans. This is made possible by their strong few- and zero-shot abilities – they can effectively learn from a handful of handcrafted, completed respo…

2023

Survival of the Most Influential Prompts: Efficient Black-Box Prompt Search via Clustering and Pruning

EMNLP 2023long findings

Prompt-based learning has been an effective paradigm for large pretrained language models (LLM), enabling few-shot or even zero-shot learning. Black-box prompt search has received growing interest recently for its distinctive properties of gradient-free optimization, proven particularly useful and p…

Cited by 0SourcecodeScholar
2023

Universal Self-Adaptive Prompting

EMNLP 2023long main

A hallmark of modern large language models (LLMs) is their impressive general zero-shot and few-shot abilities, often elicited through in-context learning (ICL) via prompting. However, while highly coveted and being the most general, zero-shot performances in LLMs are still typically weaker due to t…

Cited by 0SourceScholar
2022

Bayesian Optimization over Discrete and Mixed Spaces via Probabilistic Reparameterization

NeurIPS 2022accept

Optimizing expensive-to-evaluate black-box functions of discrete (and potentially continuous) design parameters is a ubiquitous problem in scientific and engineering applications. Bayesian optimization (BO) is a popular, sample-efficient method that leverages a probabilistic surrogate model and an…

Cited by 58SourcePDFScholar
2022

On Redundancy and Diversity in Cell-based Neural Architecture Search

ICLR 2022poster

Searching for the architecture cells is a dominant paradigm in NAS. However, little attention has been devoted to the analysis of the cell-based search spaces even though it is highly important for the continual development of NAS. In this work, we conduct an empirical post-hoc analysis of architec…

2021

Adversarial Attacks on Graph Classifiers via Bayesian Optimisation

NeurIPS 2021poster

Graph neural networks, a popular class of models effective in a wide range of graph-based learning tasks, have been shown to be vulnerable to adversarial attacks. While the majority of the literature focuses on such vulnerability in node-level classification tasks, little effort has been dedicated t…

2021

Interpretable Neural Architecture Search via Bayesian Optimisation with Weisfeiler-Lehman Kernels

ICLR 2021poster

Current neural architecture search (NAS) strategies focus only on finding a single, good, architecture. They offer little insight into why a specific network is performing well, or how we should modify the architecture if we want further improvements. We propose a Bayesian optimisation (BO) approach…

Cited by 140SourcePDFScholar
2021

Think Global and Act Local: Bayesian Optimisation over High-Dimensional Categorical and Mixed Search Spaces

ICML 2021spotlight

High-dimensional black-box optimisation remains an important yet notoriously challenging problem. Despite the success of Bayesian optimisation methods on continuous domains, domains that are categorical, or that mix continuous and categorical variables, remain challenging. We propose a novel solutio…