---
title: "Improving phonological distance measures for signs: the"
description: "The authors propose a two-part pipeline. 22 references, cited by 1 paper here. Among them: 0."
authors: ["Hope E. Morgan", "Amy Isard", "Anh Dang"]
year: 2026
venue: "Proceedings of the LREC 2026 12th Workshop on the Representation and Processing of Sign Languages: Language in Motion"
source: "https://aclanthology.org/2026.signlang-1.36/"
doi: "10.63317/3etemouixntr"
licence: "CC BY-NC 4.0 (ELRA, LREC proceedings)"
licence_url: "https://creativecommons.org/licenses/by-nc/4.0/"
summary_licence: "Elamur Cosmic License"
canonical: "https://research.elamur.ai/free/en/papers/morgan-2026-improving-phonological-distance-measures-signs/"
---
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# Improving phonological distance measures for signs: the CatFormCompare tool

**Authors:** [Hope E. Morgan](https://md.research.elamur.ai/free/en/authors/hope-e-morgan/), [Amy Isard](https://md.research.elamur.ai/free/en/authors/amy-isard/) and Anh Dang · **Year:** 2026 · **Venue:** [Proceedings of the LREC 2026 12th Workshop on the Representation and Processing of Sign Languages: Language in Motion](https://md.research.elamur.ai/free/en/venues/signlang/) ([LREC Workshop on the Representation and Processing of Sign Languages: Language in Motion 2026](https://md.research.elamur.ai/free/en/venues/signlang/2026/)) · **Publisher:** [European Language Resources Association (ELRA)](https://md.research.elamur.ai/free/en/publishers/european-language-resources-association-elra/) · **Licence:** [CC BY-NC 4.0 (ELRA, LREC proceedings)](https://creativecommons.org/licenses/by-nc/4.0/)

**Links:** [Publisher's page](https://aclanthology.org/2026.signlang-1.36/) · [PDF](https://aclanthology.org/2026.signlang-1.36.pdf) · [DOI 10.63317/3etemouixntr](https://doi.org/10.63317/3etemouixntr) · [OpenAlex](https://openalex.org/W7166549542)

**Citations:** 0 citations (OpenAlex, 2026-10-14) · [1](https://md.research.elamur.ai/free/en/papers/morgan-2026-improving-phonological-distance-measures-signs/cited-by/) in our library, of the 149,439 papers whose bibliographies we read

## Summary
Sign language phonology lacks a notation precise enough to find minimal pairs automatically. A minimal pair is two signs with different meanings that differ in only one form value. Levenshtein-style edit distances assume sequential segments, but sign features are mostly simultaneous and contrast mainly by substitution. A naive field-by-field match/no-match comparison also fails because it ignores dependencies between features; for example, an ending handshape may be predictable from the type of handshape change. The authors propose a two-part pipeline. Signs are first encoded as SL CatForm strings, and then CatFormCompare, a Python tool, compares pairs of strings while applying "conditionalities" that model these dependencies, so only linguistically meaningful differences are counted. The pipeline was evaluated on 1,880 Kenyan Sign Language (KSL) signs, with 449 previously identified same-signer minimal pairs serving as ground truth. It works in principle but still misses some pairs, notably location contrasts, and needs refinement. The work matters because it grounds phonological distance in actual linguistic structure rather than in artefacts of a coding system, and it gives schema designers a feedback loop.

## Key points
- The SL CatForm coding schema has 42 categorical variables (0–41), each value coded as one or two ASCII characters. It is based on the Dependency Model with changes inspired by the Prosodic Model, and it has previously been applied to KSL and Israeli Sign Language.
- Evaluation data: 1,880 KSL signs and 449 minimal pairs. Only pairs produced by the same signer were kept, so each pair reflects a single grammar.
- Example conditionality: handshape contours vs. handshape contrasts (variables 7, 8 and 32). In a closing contour, the contrast is in the starting handshape, while a true contrast can sit in the ending handshape.
- The tool, coding schema and a KSL data sample are released via the Hamburg University Research Data Repository (doi:10.25592/uhhfdm.18534).
- Planned next steps: diagnose mismatches, especially missed location pairs; expand the diagnostic test set; and rethink how orientation is coded.

*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

- [Universität Hamburg](https://md.research.elamur.ai/free/en/universities/universitat-hamburg/) — University, Hamburg, Germany · 79 works · 5,422 citations
- [Utrecht University](https://md.research.elamur.ai/free/en/universities/utrecht-university/) — University, Utrecht, Netherlands · 39 works · 1,603 citations

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## Cite

Cite as: Hope E. Morgan, Amy Isard and Anh Dang. 2026. Improving phonological distance measures for signs: the CatFormCompare tool. Proceedings of the LREC 2026 12th Workshop on the Representation and Processing of Sign Languages: Language in Motion.

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

```bibtex
@inproceedings{morgan2026improving,
  title = {{Improving phonological distance measures for signs: the CatFormCompare tool}},
  author = {Hope E. Morgan, Amy Isard and Anh Dang},
  booktitle = {Proceedings of the LREC 2026 12th Workshop on the Representation and Processing of Sign Languages: Language in Motion},
  year = {2026},
  doi = {10.63317/3etemouixntr},
  url = {https://doi.org/10.63317/3etemouixntr}
}
```

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## References

22 references, 1 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 31 October 2026*