---
license: apache-2.0
library_name: transformers
pipeline_tag: text-generation
---

# SPADER: Step-wise Peer Advantage with Diversity-Aware Exploration Rewards for Multi-Answer Question Answering

This is the `qwen3-8b-spader` checkpoint presented in [SPADER: Step-wise Peer Advantage with Diversity-Aware Exploration Rewards for Multi-Answer Question Answering](https://huggingface.co/papers/2606.00593).

SPADER is a reinforcement learning framework for long-horizon tool use in Multi-Answer QA. It includes Step-wise Peer Advantage (SPA), a critic-free step-level credit assignment mechanism that aligns parallel trajectories by decision step and estimates advantages from peer returns. It also includes a diversity-aware exploration reward that promotes long-tail entity discovery by upweighting rare findings and downweighting redundant ones.

## Links

- **Paper**: [arXiv:2606.00593](https://huggingface.co/papers/2606.00593)
- **Code**: [GitHub Repository](https://github.com/KhanCold/spader)

## Citation

```bibtex
@misc{shi2026spaderstepwisepeeradvantage,
      title={SPADER: Step-wise Peer Advantage with Diversity-Aware Exploration Rewards for Multi-Answer Question Answering}, 
      author={Qiming Shi and Zhaolu Kang and Yunfan Zhou and Di Weng and Yingcai Wu},
      year={2026},
      eprint={2606.00593},
      archivePrefix={arXiv},
      primaryClass={cs.CL},
      url={https://arxiv.org/abs/2606.00593}, 
}
```