Machine Heart

Oct 18, 2026 · Artificial Intelligence

SPADER: Step-wise GRPO with Diversity-Aware Rewards Boosts Long-Tail Answer Discovery in Multi-Answer QA

SPADER introduces a step-wise GRPO framework with diversity-aware exploration rewards to improve long-tail answer coverage in multi-answer question answering, achieving state-of-the-art results across four benchmarks and two base models by refining credit assignment and incentivizing rare entity discovery.