Overview
RAMQA (arXiv:2501.13297, published 2025-01-23) is a unified framework for multi-modal retrieval-augmented question answering (MRAQA), authored by Yang Bai, Christan Earl Grant, and Daisy Zhe Wang.
Background
MRAQA, which integrates text and images, has gained significant attention in information retrieval (IR) and natural language processing (NLP). Traditional ranking methods rely on small encoder-based language models, which are incompatible with modern decoder-based generative large language models (LLMs) that have advanced various NLP tasks.
Method
To bridge this gap, RAMQA combines learning-to-rank methods with generative permutation-enhanced ranking techniques:
1. Pointwise multi-modal ranker: trained using LLaVA as the backbone. 2. Generative re-ranker: a LLaMA model is instruction-tuned to re-rank the top-k documents using an autoregressive multi-task learning approach. 3. Permutation-enhanced ranking: the generative ranking model outputs re-ranked document IDs and specific answers from document candidates in various permutations.
Results
Experiments on two MRAQA benchmarks, WebQA and MultiModalQA, show significant improvements over strong baselines, demonstrating the effectiveness of the unified retrieval-ranking-generation approach.
Broader Context
The work sits at the intersection of RAG and large-scale search/recommendation systems. Notable insights for the field include:
- Cascaded retrieval + re-ranking + generation remains the mainstream architecture, but agentic paradigms are making retrieval strategy itself a learnable object.
- High-quality instruction data matters as much as click/session logs; synthetic data must guard against knowledge leakage and distribution shift.
- The gap between offline metrics and online satisfaction is widening; LLM-as-judge evaluation needs cross-validation with human assessment.
- Latency, cost, explainability, and safety policies are hard constraints for industrial deployment.
- Paper: https://arxiv.org/abs/2501.13297
- Code and data: https://github.com/TonyBY/RAMQA