🤖 AI Summary
Existing open-source vision-language models exhibit limited performance on complex cross-modal tasks requiring fine-grained perception and multi-step reasoning—e.g., visual grounding, OCR parsing, mathematical, and spatial reasoning. To address this, we propose TACO, a multimodal large action model introducing the “Chain-of-Thought-and-Action” (CoTA) paradigm, which explicitly models reasoning as executable sequences of cognitive steps and tool invocations. Methodologically: (1) We synthesize one million high-quality CoTA trajectories using GPT-4o and Python program generation, augmented by rigorous data filtering and mixture strategies; (2) We design an end-to-end framework for joint thought–action modeling, integrating external tools including OCR, depth estimation, and calculator modules; (3) We move beyond conventional single-step instruction tuning. Evaluated across eight benchmarks, TACO achieves an average 3.6% absolute improvement over strong baselines, with a 15% gain on MMVet, demonstrating substantial advances in fine-grained perception and compositional reasoning.
📝 Abstract
While open-source multi-modal language models perform well on simple question answering tasks, they often fail on complex questions that require multiple capabilities, such as fine-grained recognition, visual grounding, and reasoning, and that demand multi-step solutions. We present TACO, a family of multi-modal large action models designed to improve performance on such complex, multi-step, and multi-modal tasks. During inference, TACO produces chains-of-thought-and-action (CoTA), executes intermediate steps by invoking external tools such as OCR, depth estimation and calculator, then integrates both the thoughts and action outputs to produce coherent responses. To train TACO, we create a large dataset of over 1M synthetic CoTA traces generated with GPT-4o and Python programs. We then experiment with various data filtering and mixing techniques and obtain a final subset of 293K high-quality CoTA examples. This dataset enables TACO to learn complex reasoning and action paths, surpassing existing models trained on instruction tuning data with only direct answers. Our model TACO outperforms the instruction-tuned baseline across 8 benchmarks, achieving a 3.6% improvement on average, with gains of up to 15% in MMVet tasks involving OCR, mathematical reasoning, and spatial reasoning. Training on high-quality CoTA traces sets a new standard for complex multi-modal reasoning, highlighting the need for structured, multi-step instruction tuning in advancing open-source mutli-modal models' capabilities.