HELIOS

Harmonizing Early Fusion, Late Fusion, and LLM Reasoning for Multi-Granular Table-Text Retrieval

HELIOS represents a breakthrough in multi-modal information retrieval, specifically targeting the complex challenge of retrieving relevant information from both structured tables and unstructured text simultaneously.

Key Innovation

HELIOS formulates retrieval as finding a query-relevant subgraph within a bipartite data graph built via early fusion of table segments and passages. The system introduces a three-stage pipeline that strategically integrates:

  1. Early Fusion: Combining table segments and text passages at the data level
  2. Late Fusion: Merging retrieval results from different modalities
  3. LLM Reasoning: Leveraging large language models for complex logical inference

Problem Statement

Traditional retrieval methods, which rely solely on semantic similarity, struggle with tasks requiring advanced logical inference such as:

  • Column-wise aggregation across tables
  • Multi-hop reasoning between tables and text
  • Complex analytical queries spanning multiple data modalities

Solution Approach

HELIOS addresses these limitations by:

  • Graph-Based Retrieval: Modeling the retrieval task as subgraph selection within a bipartite data graph
  • Multi-Granular Processing: Operating at different levels of granularity for optimal performance
  • Integrated Reasoning: Incorporating LLM reasoning capabilities to handle complex logical operations

Results

The optimized retrieval method significantly outperforms existing approaches on benchmark datasets, demonstrating the effectiveness of harmonizing different fusion strategies with advanced reasoning capabilities.

Publication

Accepted at ACL 2025 Main - one of the top venues in computational linguistics and natural language processing.

(Park et al., 2025)

References

2025

  1. ACL
    helios.jpg
    HELIOS: Harmonizing Early Fusion, Late Fusion, and LLM Reasoning for Multi-Granular Table-Text Retrieval
    Sungho Park, Joohyung Yun, Jongwuk Lee, and 1 more author
    In Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), 2025