ARC: Fair Relative Advantage Comparison in Open-Ended Real-World Interaction
Organizations: Ant International
Abstract
Open-ended real-world interaction admits multiple valid behaviors: an agent may answer directly, ask for clarification, provide progress updates, or confirm before acting. This flexibility breaks a core assumption behind group-based RL: rollouts compared within a group are no longer guaranteed to be behaviorally comparable. As a result, reward-model preferences over interaction style can distort relative advantages and steer optimization toward reward-preferred behaviors rather than context-appropriate ones. We formalize this as a \textit{reward fairness problem} and propose \textbf{ARC} (Advantage Regularization via Conditioning), a training recipe that restores fairer relative comparison through strategy-conditioned rollout grouping, together with hybrid rewards and entropy regularization. We study ARC in our proposed \inter, a novel paradigm for responsive, steerable, and execution-aware user-agent interaction that decouples user-visible communication from latent reasoning and tool use. \inter\ also provides the annotation and distillation pipeline for constructing \inter-86K, our strategy-annotated training corpus for supervised and RL training. Empirically, ARC substantially strengthens the core tool-use benchmarks, while \inter\ reduces time-to-first-token from 4.91s to 1.27s relative to a think-style baseline. Together, these results suggest that a central bottleneck in open-ended interactive learning is not only how agents are rewarded, but whether their behaviors are compared fairly in the first place. The ARC implementation and \inter-86K training data will be released.
Figures & tables
| Category | Strategy | Description |
| Progress Update | Tool Execute | Execute single or sequential tool calls; return the final answer upon completion |
| Parallel Tools | Execute independent tool calls simultaneously; synthesize combined results | |
| Multi-Step Update | Stream incremental progress updates to the user between sequential sub-tasks | |
| Silent Execution | Execute tool calls without emitting user-visible output when intermediate steps are irrelevant | |
| Error Recovery | Handle tool failures gracefully and recover with corrective actions | |
| Clarify First | Clarify First | Ask the user for missing or ambiguous information before executing any tool call |
| Statistic | Value |
|---|---|
| Total examples | 86,796 |
| Token Statistics | |
| Average input tokens | 702.1 |
| Average output tokens | 264.5 |
| Average total tokens | 966.6 |
| Tool Statistics | |
| Method | Avg. | TTFT | Tool Calling | Reasoning | Instruction Following | Alignment | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| -airline | -retail | -airline | -retail | -telecom | AIME 2026 | GPQA-D | HMMT 2025 | IFBench | ArenaHard | |||
| Baselines | ||||||||||||
| Qwen3-8B-noThink | 22.85 | 0.05s | 12.00 | 29.86 | 14.61 | 36.55 | 17.80 | 17.08 | 45.71 | 12.92 | 24.83 | 17.14 |
| Qwen3-8B-Think | 32.82 | 4.91s | 28.00 | 36.81 | 29.75 | 38.71 | 23.46 | 47.92 | 53.54 | 20.83 | 19.43 | 29.83 |
| RL Backbones | ||||||||||||
| PPO | 27.49 | 0.45s | 35.33 | 41.45 | 33.33 | 38.89 | 19.01 | 30.83 | 38.70 | 8.75 | 19.73 | 8.88 |
| Method | Avg. | airline | retail | airline | retail | telecom |
|---|---|---|---|---|---|---|
| Qwen3-4B-noThink | 22.38 | 20.00 | 22.32 | 21.40 | 26.31 | 21.90 |
| Qwen3-4B-Think | 29.54 | 27.51 | 37.10 | 28.07 | 29.21 | 25.83 |
| GRPO (4B) | 22.33 | 29.33 | 10.72 | 36.94 | 15.96 | 18.69 |
| GRPO+ARC (4B) | 34.23 | 29.33 | 40.00 | 32.00 | 39.77 | 30.03 |
| Training Setting | Avg. | Avg. | Avg. | Reasoning Avg. | IFBench | ArenaHard |
|---|---|---|---|---|---|---|
| No removal (ARC default) | 29.59 | 47.00 | 38.22 | 31.58 | 15.99 | 15.18 |
| Linear removal | 27.28 | 38.21 | 31.83 | 34.12 | 16.33 | 15.92 |
| Constant removal | 26.97 | 34.97 | 32.99 | 33.21 | 18.71 | 15.01 |
| Strategy Segment | Avg. | Avg. | Avg. | Reasoning Avg. | IFBench | ArenaHard |
|---|---|---|---|---|---|---|
| Progress Update | 21.74 | 23.62 | 22.36 | 34.01 | 16.33 | 14.27 |
| Progress Update + Direct Answer | 24.91 | 31.67 | 32.46 | 27.79 | 17.69 | 14.96 |
| Progress Update + Direct Answer + Clarify First | 25.60 | 31.04 | 28.97 | 35.21 | 16.67 | 16.13 |
| Full Suite (4) | 29.59 | 47.00 | 38.22 | 31.58 | 15.99 | 15.18 |
Appendix figures & tables8 assets
Supplementary material from the paper’s appendix.
Appendix
| Reward Comparisons | Avg. | Avg. | Avg. | Reasoning Avg. | IFBench | ArenaHard |
|---|---|---|---|---|---|---|
| Partial tool + answer judge | 24.90 | 30.92 | 29.16 | 33.19 | 14.97 | 16.24 |
| Exact tool + answer judge | 27.89 | 37.31 | 31.94 | 36.24 | 18.03 | 15.94 |
| Penalized tool + gated judge | 27.98 | 43.93 | 36.49 | 29.60 | 16.33 | 13.57 |
| Judge Model | Avg. | Avg. | Avg. | Reasoning Avg. | IFBench | ArenaHard |
|---|---|---|---|---|---|---|
| Qwen3-235B-Instruct | 27.98 | 43.93 | 36.49 | 29.60 | 16.33 | 13.57 |
| Qwen3.5-27B | 21.67 | 25.69 | 22.55 | 27.97 | 19.39 | 12.77 |
| Qwen3.5-122B | 25.02 | 35.22 | 30.70 | 29.27 | 16.67 | 13.27 |
| Configuration | Avg. | Avg. | Avg. | Reasoning Avg. | IFBench | ArenaHard |
|---|---|---|---|---|---|---|
| Training Ingredients | ||||||
| GRPO | 25.43 | 35.81 | 31.72 | 27.25 | 18.71 | 13.66 |
| GRPO + Entropy | 24.23 | 33.53 | 29.42 | 27.66 | 16.67 | 13.85 |
| GRPO + Strategy-Conditioned Grouping | 27.80 | 43.93 | 35.55 | 29.60 | 16.33 | 13.57 |
| GRPO + Strategy-Conditioned Grouping + Entropy | 29.59 | 47.00 | 38.22 | 31.58 | 15.99 | 15.18 |
| Entropy Sensitivity (with Strategy-Conditioned Grouping) | ||||||
| Method | Ratio (95% CI) | ||
|---|---|---|---|
| GRPO | 0.0555 | 0.1331 | 0.417 [0.002, 3.015] |
| ARC | 0.0030 | 0.0401 | 0.074 [0.002, 0.410] |
| Method | Tool-use Avg. | - Airline | - Retail | - Airline | - Retail | - Telecom |
|---|---|---|---|---|---|---|
| GRPO | 33.35 | |||||
| GRPO + ARC | 41.73 | |||||
| GRPO + ARC, 50% corrupted | 35.01 |
| Method | Tool-use Avg. | -Airline | -Retail | -Airline | -Retail | -Telecom |
|---|---|---|---|---|---|---|
| Qwen3-8B-NoThink | ||||||
| Qwen3-8B-Think | ||||||
| PPO | ||||||
| PPO + ARC | ||||||
| DAPO | ||||||
| DAPO + ARC |
| Method | Tool-use Avg. | -Airline | -Retail | -Airline | -Retail | -Telecom |
|---|---|---|---|---|---|---|
| PPO | ||||||
| PPO + ARC | ||||||
| DAPO | ||||||
| DAPO + ARC | ||||||
| GRPO | ||||||
| GRPO + ARC |
| Parameter | Value |
|---|---|
| Base Model | Qwen3-8B |
| Learning Rate | 1e-6 |
| Batch Size | 64 |
| PPO Mini Batch Size | 8 |
| PPO Micro Batch Size (per GPU) | 4 |
| Max Prompt Length | 6000 |