---
license: cc-by-nc-4.0
task_categories:
  - question-answering
language:
  - en
tags:
  - reasoning
  - mathematics
  - physics
  - chemistry
  - jee
  - failure-analysis
  - contamination-aware
size_categories:
  - n<1K
extra_gated_prompt: "Please share your details to instantly access this sample dataset. Your request is auto-approved."
extra_gated_fields:
  Name: text
  Email: text
  Organization: text
  Intended use: text
---

# NULLSPACE

**267 JEE questions frontier models get wrong — every answer key independently verified, every row tagged for contamination.** This is a 10-row sample. Access is auto-approved — fill in your details to view the data.

> Full dataset (267 questions · 77 held out): [Nalandadata/NULLSPACE](https://huggingface.co/datasets/Nalandadata/NULLSPACE) — requires access request.

NULLSPACE is a failure-only benchmark. A question enters the set only when multiple frontier models independently get it wrong and the answer key has been re-verified. Each row carries a `do_not_score` field listing models that must be excluded when scoring — because those models' failures were used to build the set, scoring them on it measures nothing. Clean accuracy (67.3%) is higher than overall accuracy (62.2%) because contaminated rows are the ones models specifically struggled with.

---

## Sample coverage

| item_id | Subject | Answer type | Figures |
|---|---|---|---|
| STEM-0001 | Mathematics | multiple_choice | 0 |
| STEM-0002 | Chemistry | single_choice | 5 |
| STEM-0003 | Chemistry | matrix_match | 4 |
| STEM-0004 | Chemistry | numerical | 0 |
| STEM-0005 | Mathematics | multiple_choice | 0 |
| STEM-0006 | Physics | integer | 0 |
| STEM-0008 | Chemistry | multiple_choice | 5 |
| STEM-0010 | Physics | single_choice | 1 |
| STEM-0015 | Mathematics | single_choice | 0 |
| STEM-0020 | Chemistry | integer | 1 |

## Schema (14 columns)

| Field | Meaning |
|---|---|
| `item_id` | Stable public identifier, `STEM-NNNN` |
| `exam`, `subject`, `answer_type` | Source and question format |
| `question`, `options`, `column_a`/`column_b` | Question content with HTML/MathML |
| `answer`, `answer_key` | The key — plain string and structured object |
| **`do_not_score`** | **Models that must be excluded when scoring this row** |
| `models_failed` | Which models got this question wrong |
| `verdict` | `CONFIRMED_MODEL_FAILURE`, `DISPUTED_BUT_KEY_BACKED`, `DISPUTED` |
| `thumbnail` | First figure image (`Image` type), null for text-only |

## Citation

```bibtex
@misc{nullspace2026,
  title        = {NULLSPACE: A Failure-Only JEE Benchmark with Contamination Tracking},
  author       = {Nalandadata},
  year         = {2026},
  howpublished = {\url{https://huggingface.co/datasets/Nalandadata/NULLSPACE}},
  note         = {267 public questions; 77 held out}
}
```

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[info@nalandadata.ai](mailto:info@nalandadata.ai) · [nalandadata.ai](https://nalandadata.ai)