---
license: apache-2.0
language:
- en
pretty_name: Molmo2-ER SIMS-VSI
tags:
- embodied-reasoning
- molmo2
- molmo2-er
- vlm-training-data
---

# Molmo2-ER · ellisbrown/SIMS-VSI

203K simulated video spatial QA pairs from AI2-THOR/ProcTHOR agent trajectories.

This is a re-hosted, **loader-ready subset** of the upstream dataset, used to train [`allenai/Molmo2-ER-4B`](https://huggingface.co/allenai/Molmo2-ER-4B). Files mirror the upstream layout; nothing in the data has been modified.

## Upstream source

- **Original dataset:** [ellisbrown/SIMS-VSI](https://huggingface.co/datasets/ellisbrown/SIMS-VSI)
- **Paper:** *SIMS-V: Simulated Instruction-Tuning for Spatial Video Understanding* ([arXiv:2511.04668](https://arxiv.org/abs/2511.04668))
- **License:** `apache-2.0` (inherits from upstream)

If you use this data, please cite the original authors:

```bibtex
@misc{brown2025simsvsimulatedinstructiontuningspatial,
  title={SIMS-V: Simulated Instruction-Tuning for Spatial Video Understanding},
  author={Ellis Brown and Arijit Ray and Ranjay Krishna and others},
  year={2025},
  eprint={2511.04668},
  archivePrefix={arXiv}
}
```

## Extracting before training

This release ships archives. Extract them in-place before pointing `SPATIAL_DATA_HOME` at this directory:

```bash
zstd -d annos_shard_000.tar.zst && tar -xf annos_shard_000.tar
for f in video_shard_*.tar.zst; do zstd -d $f -o ${f%.zst}; done
for f in video_shard_*.tar; do tar -xf $f; done
# Loader expects ./data/<shards>/...
```

## Usage in Molmo2-ER

See the [`allenai/molmo2`](https://github.com/allenai/molmo2) repository for the data loader and training recipe. The relevant loader class for this dataset lives in `olmo/data/spatial_datasets.py`.