Benchmarking Multimodal Retrieval Augmented Generation with Dynamic VQA Dataset and Self-adaptive Planning Agent
Yangning Li, Yinghui Li, Xinyu Wang, Yong Jiang, Zhen Zhang, Xinran Zheng, Hui Wang, Hai-Tao Zheng, Philip S. Yu, Fei Huang, Jingren Zhou
TL;DR
The paper argues that fixed, non-adaptive retrieval in multimodal RAG systems leads to non-adaptive and overloaded queries,欠 and introduces Dyn-VQA to benchmark dynamic, multimodal knowledge retrieval. It proposes OmniSearch, a self-adaptive planning agent that decomposes complex multimodal questions into sub-questions and iteratively retrieves information using diverse tools. Empirical results show OmniSearch, especially with GPT-4V as the sub-question solver, substantially improves over heuristic mRAG baselines and commercial generative search engines, though challenges remain on fast-changing and high-hop scenarios. The work provides a new dataset and a plug-and-play retrieval framework that advances robust, adaptive multimodal QA and offers open-source resources for the community.
Abstract
Multimodal Retrieval Augmented Generation (mRAG) plays an important role in mitigating the "hallucination" issue inherent in multimodal large language models (MLLMs). Although promising, existing heuristic mRAGs typically predefined fixed retrieval processes, which causes two issues: (1) Non-adaptive Retrieval Queries. (2) Overloaded Retrieval Queries. However, these flaws cannot be adequately reflected by current knowledge-seeking visual question answering (VQA) datasets, since the most required knowledge can be readily obtained with a standard two-step retrieval. To bridge the dataset gap, we first construct Dyn-VQA dataset, consisting of three types of "dynamic" questions, which require complex knowledge retrieval strategies variable in query, tool, and time: (1) Questions with rapidly changing answers. (2) Questions requiring multi-modal knowledge. (3) Multi-hop questions. Experiments on Dyn-VQA reveal that existing heuristic mRAGs struggle to provide sufficient and precisely relevant knowledge for dynamic questions due to their rigid retrieval processes. Hence, we further propose the first self-adaptive planning agent for multimodal retrieval, OmniSearch. The underlying idea is to emulate the human behavior in question solution which dynamically decomposes complex multimodal questions into sub-question chains with retrieval action. Extensive experiments prove the effectiveness of our OmniSearch, also provide direction for advancing mRAG. The code and dataset will be open-sourced at https://github.com/Alibaba-NLP/OmniSearch.
