---
title: "Mr. TyDi: A Multi-lingual Benchmark for Dense Retrieval (2021)"
description: "The authors build Mr. TyDi, an open-retrieval version of TyDi. 24 references, cited by 78 papers here."
authors: ["Xinyu Zhang", "Xueguang Ma", "Peng Shi", "Jimmy Lin"]
year: 2021
venue: "Proceedings of the 1st Workshop on Multilingual Representation Learning"
source: "https://aclanthology.org/2021.mrl-1.12/"
doi: "10.18653/v1/2021.mrl-1.12"
arxiv: "2108.08787"
licence: "CC BY 4.0 (ACL Anthology)"
licence_url: "https://creativecommons.org/licenses/by/4.0/"
summary_licence: "Elamur Cosmic License"
canonical: "https://research.elamur.ai/free/en/papers/zhang-2021-mr-tydi-multi-lingual-benchmark/"
---
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# Mr. TyDi: A Multi-lingual Benchmark for Dense Retrieval

**Authors:** [Xinyu Zhang](https://md.research.elamur.ai/free/en/authors/xinyu-zhang/), [Xueguang Ma](https://md.research.elamur.ai/free/en/authors/xueguang-ma/), [Peng Shi](https://md.research.elamur.ai/free/en/authors/peng-shi/) and [Jimmy Lin](https://md.research.elamur.ai/free/en/authors/jimmy-lin/) · **Year:** 2021 · **Venue:** [Proceedings of the 1st Workshop on Multilingual Representation Learning](https://md.research.elamur.ai/free/en/venues/mrl/) ([Workshop on Multilingual Representation Learning 2021](https://md.research.elamur.ai/free/en/venues/mrl/2021/)) · **Publisher:** [Association for Computational Linguistics](https://md.research.elamur.ai/free/en/publishers/association-for-computational-linguistics/) · **Licence:** [CC BY 4.0 (ACL Anthology)](https://creativecommons.org/licenses/by/4.0/)

**Links:** [Publisher's page](https://aclanthology.org/2021.mrl-1.12/) · [PDF](https://aclanthology.org/2021.mrl-1.12.pdf) · [DOI 10.18653/v1/2021.mrl-1.12](https://doi.org/10.18653/v1/2021.mrl-1.12) · [arXiv 2108.08787](https://arxiv.org/abs/2108.08787) · [OpenAlex](https://openalex.org/W3214151748)

**Citations:** 51 citations (OpenAlex, 2026-10-14) · [78](https://md.research.elamur.ai/free/en/papers/zhang-2021-mr-tydi-multi-lingual-benchmark/cited-by/) in our library, of the 149,439 papers whose bibliographies we read

## Summary
Dense retrieval models are usually trained on English data. They are known to degrade on out-of-distribution input, but how they behave in other languages has been poorly studied. Existing resources do not fill this gap. TyDi is essentially a reading-comprehension task over pre-selected articles, XOR-TyDi targets English Wikipedia (cross-lingual), and MKQA relies on translated, entity-centred questions. The authors build Mr. TyDi, an open-retrieval version of TyDi. Questions in eleven typologically diverse languages must be answered by searching the full Wikipedia of the same language, using the original TyDi dumps. As zero-shot baselines they compare BM25, a multi-lingual DPR variant called mDPR, and a sparse–dense hybrid. On its own, mDPR is far weaker than BM25. Still, combining it with BM25 improves results, which shows that even weak dense representations carry useful relevance signals. The benchmark gives a foundation for studying the robustness of dense retrieval beyond English and for expanding information access in non-English languages.

## Key points
- **Coverage:** Mr. TyDi handles mono-lingual retrieval only, with queries and passages in the same language. The benchmark spans eleven languages: English, Finnish, Russian, Arabic, Swahili, Bengali, Telugu, Thai, Indonesian, Japanese and Korean.
- **Training data size:** The number of training questions varies widely by language, from 12,377 for Arabic down to 1,295 for Korean.
- **Baseline results:** mDPR was evaluated without language-specific fine-tuning and lags BM25. The BM25+mDPR hybrid outperforms BM25 alone.
- **Where hybrid gains come from:**
  - Bengali, Indonesian, Swahili and Telugu gain mostly through better recall.
  - Thai gains mainly through better ranking.
  - The remaining languages improve on both recall and ranking.
- **Availability and future work:** The dataset is published at github.com/castorini/mr.tydi. Planned next steps include multi-step fine-tuning strategies and using the benchmark to examine multi-lingual transformer models.

*Our summary of the paper, in our own words — not its text. The work belongs to its authors; read it at the links above.*

## Institutions

- [University of Waterloo](https://md.research.elamur.ai/free/en/universities/university-of-waterloo/) — University, Waterloo, Canada · 80 works · 15,030 citations

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## Cite

Cite as: Xinyu Zhang, Xueguang Ma, Peng Shi and Jimmy Lin. 2021. Mr. TyDi: A Multi-lingual Benchmark for Dense Retrieval. Proceedings of the 1st Workshop on Multilingual Representation Learning.

The paper itself, not this page. BibTeX from the library's record of the work.

```bibtex
@inproceedings{zhang2021mr,
  title = {{Mr. TyDi: A Multi-lingual Benchmark for Dense Retrieval}},
  author = {Xinyu Zhang, Xueguang Ma, Peng Shi and Jimmy Lin},
  booktitle = {Proceedings of the 1st Workshop on Multilingual Representation Learning},
  year = {2021},
  doi = {10.18653/v1/2021.mrl-1.12},
  eprint = {2108.08787},
  archivePrefix = {arXiv},
  url = {https://doi.org/10.18653/v1/2021.mrl-1.12}
}
```

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## References

24 references, 15 of them with a card of ours. ↗ leads to the work, «find» searches for one we have no id for yet.

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*Updated 2 November 2026*
