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Xiangchen Song

16 accepted papers

2026

CausalGame: Benchmarking Causal Thinking of LLM Agents in Games

ICML 2026oral

Recently, it has received growing attention in building AI Scientist agents with Large Language Models (LLMs). Since scientific discovery fundamentally relies on uncovering causal relationships from observations, the capability of causal thinking that distinguish causation from correlation and hidde…

Cited by 0SourceScholar
2026

From Reasoning Traces to Reusable Modules: Reinforcement Learning for Compositional Generalization in Language Model Reasoning

ICML 2026poster

Reinforcement learning (RL) has emerged as a key mechanism for transforming LLMs into robust reasoners. While supervised fine-tuning (SFT) often limits models to the distribution of observed reasoning traces, RL post-training significantly improves performance on out-of-distribution (OOD) tasks that…

Cited by 0SourceScholar
2026

Score-based Greedy Search for Structure Identification of Partially Observed Linear Causal Models

ICLR 2026poster

Identifying the structure of a partially observed causal system is essential to various scientific fields. Recent advances have focused on constraint-based causal discovery to solve this problem, and yet in practice these methods often face challenges related to multiple testing and error propagatio…

Cited by 0SourceScholar
2025

LLM Interpretability with Identifiable Temporal-Instantaneous Representation

NeurIPS 2025poster

Despite Large Language Models' remarkable capabilities, understanding their internal representations remains challenging. Mechanistic interpretability tools such as sparse autoencoders (SAEs) were developed to extract interpretable features from LLMs but lack temporal dependency modeling, instantane…

Cited by 0SourceScholar
2025

On the Identification of Temporal Causal Representation with Instantaneous Dependence

ICLR 2025oral

Temporally causal representation learning aims to identify the latent causal process from time series observations, but most methods require the assumption that the latent causal processes do not have instantaneous relations. Although some recent methods achieve identifiability in the instantaneous…

Cited by 6SourcePDFScholar
2025

Reflection-Window Decoding: Text Generation with Selective Refinement

ICML 2025poster

The autoregressive decoding for text generation in large language models (LLMs), while widely used, is inherently suboptimal due to the lack of a built-in mechanism to perform refinement and/or correction of the generated content. In this paper, we consider optimality in terms of the joint probabili…

Cited by 2SourcePDFScholar
2024

A Versatile Causal Discovery Framework to Allow Causally-Related Hidden Variables

ICLR 2024poster

Most existing causal discovery methods rely on the assumption of no latent confounders, limiting their applicability in solving real-life problems. In this paper, we introduce a novel, versatile framework for causal discovery that accommodates the presence of causally-related hidden variables almost…

Cited by 17SourcePDFScholar
2024

CaRiNG: Learning Temporal Causal Representation under Non-Invertible Generation Process

ICML 2024poster

Identifying the underlying time-delayed latent causal processes in sequential data is vital for grasping temporal dynamics and making downstream reasoning. While some recent methods can robustly identify these latent causal variables, they rely on strict assumptions about the invertible generation p…

2024

Causal Temporal Representation Learning with Nonstationary Sparse Transition

NeurIPS 2024poster

Causal Temporal Representation Learning (Ctrl) methods aim to identify the temporal causal dynamics of complex nonstationary temporal sequences. Despite the success of existing Ctrl methods, they require either directly observing the domain variables or assuming a Markov prior on them. Such requirem…

2023

Estimating Treatment Effects from Irregular Time Series Observations with Hidden Confounders

AAAI 2023technical

Causal analysis for time series data, in particular estimating individualized treatment effect (ITE), is a key task in many real world applications, such as finance, retail, healthcare, etc. Real world time series, i.e., large-scale irregular or sparse and intermittent time series, raise significan…

Cited by 20SourcePDFScholar
2023

PLOT: Prompt Learning with Optimal Transport for Vision-Language Models

ICLR 2023top-25%

With the increasing attention to large vision-language models such as CLIP, there has been a significant amount of effort dedicated to building efficient prompts. Unlike conventional methods of only learning one single prompt, we propose to learn multiple comprehensive prompts to describe diverse ch…

2023

Temporally Disentangled Representation Learning under Unknown Nonstationarity

NeurIPS 2023poster

In unsupervised causal representation learning for sequential data with time-delayed latent causal influences, strong identifiability results for the disentanglement of causally-related latent variables have been established in stationary settings by leveraging temporal structure. However, in nonsta…

2022

Creating Training Sets via Weak Indirect Supervision

ICLR 2022poster

Creating labeled training sets has become one of the major roadblocks in machine learning. To address this, recent Weak Supervision (WS) frameworks synthesize training labels from multiple potentially noisy supervision sources. However, existing frameworks are restricted to supervision sources that…

Cited by 19SourcePDFScholar
2021

COVID-19 Literature Knowledge Graph Construction and Drug Repurposing Report Generation

NAACL 2021system demonstrations

To combat COVID-19, both clinicians and scientists need to digest the vast amount of relevant biomedical knowledge in literature to understand the disease mechanism and the related biological functions. We have developed a novel and comprehensive knowledge discovery framework, COVID-KG to extract fi…

2021

ChemNER: Fine-Grained Chemistry Named Entity Recognition with Ontology-Guided Distant Supervision

EMNLP 2021main

Scientific literature analysis needs fine-grained named entity recognition (NER) to provide a wide range of information for scientific discovery. For example, chemistry research needs to study dozens to hundreds of distinct, fine-grained entity types, making consistent and accurate annotation diffic…

2021

Taxonomy Completion via Triplet Matching Network

AAAI 2021technical

Automatically constructing taxonomy finds many applications in e-commerce and web search. One critical challenge is as data and business scope grow in real applications, new concepts are emerging and needed to be added to the existing taxonomy. Previous approaches focus on the taxonomy expansion, i.…