adversarial nli
**Adversarial NLI (ANLI)** is a **difficult NLI benchmark created through human-in-the-loop adversarial data collection** — examples that humans create specifically to fool state-of-the-art models, testing robust language understanding.
**What Is Adversarial NLI?**
- **Type**: Natural Language Inference benchmark.
- **Method**: Humans write premise-hypothesis pairs that fool models.
- **Difficulty**: Much harder than standard NLI datasets.
- **Rounds**: Three rounds of increasingly difficult examples.
- **Purpose**: Test model robustness and reasoning depth.
**Why ANLI Matters**
- **Robustness**: Exposes model weaknesses and shortcuts.
- **Harder**: Models that ace SNLI/MultiNLI struggle on ANLI.
- **Iterative**: Each round targets remaining model failures.
- **Real Reasoning**: Requires genuine understanding, not shortcuts.
- **Research Standard**: Used to evaluate robust NLU models.
**Collection Process**
1. Human sees premise and model prediction.
2. Human writes hypothesis to fool the model.
3. If model fails, example added to dataset.
4. Repeat with improved models for harder rounds.
**Performance Gap**
- BERT on MultiNLI: ~86%
- BERT on ANLI: ~45% (near random)
ANLI is the **stress test for language understanding** — exposing shortcuts models learn.