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HFEPX · Eval paper review

Scaling Unsupervised Word Alignment to Documents via Structural Constraints

Michelle Wastl, Jannis Vamvas, Rico Sennrich

Published

Aug 21, 2026

Citations

0

Trust level

Low

Usefulness score

0/100 (Low)

Extraction confidence

35% (Low)

Derived from extracted protocol signals and abstract evidence.

Rater population

Not reported

Signals refreshed

Aug 21, 2026

Should you rely on this paper?

This paper is adjacent to HFEPX scope and is best used for background context, not as a primary protocol reference.

Use this as background context only. Do not make protocol decisions from this page alone.

Best use

Background context only

Use if you need

A secondary eval reference to pair with stronger protocol papers.

What to verify

Validate the evaluation procedure and quality controls in the full paper before operational use.

Main weakness

This paper looks adjacent to evaluation work, but not like a strong protocol reference.

Human feedback signal
Not explicit
Not explicit in abstract metadata
Evaluation signal
Detected
Eval setup described
Usefulness for eval research
0/100
Adjacent candidate

Treat as adjacent context, not a core eval-method reference.

Abstract

Word alignment has traditionally been studied between sentences, but many cross-lingual tasks increasingly require correspondences across full documents. While recent multilingual embedding models can encode long inputs, we show that applying algorithms designed for sentences directly to documents leads to performance degradation. To address this, we introduce CTFAlign, a lightweight, training-free approach for document-level word alignment. CTFAlign applies a coarse-to-fine refinement strategy that restricts the alignment search space to semantically similar regions. Additionally, we introduce MDPAlign, a simpler alternative that constrains alignments by position with a main diagonal prior. Both approaches operate directly on full documents without relying on sentence segmentation or sentence alignment. We evaluate these methods across six language pairs varying in typological distance, resourcedness, and document length. Averaged over three models, CTFAlign reduces word alignment error rate from 0.412 to 0.326. These gains transfer downstream, leading to improvements in document-level translation coverage evaluation and recognition of semantic differences. We release CTFAlign as a Python package and make the code and data to reproduce our experiments publicly available.

What we could verify

These are the protocol signals we could actually recover from the available paper metadata. Use them to decide whether this paper is worth deeper reading.

Human Feedback Types

missing

None explicit

No explicit feedback protocol extracted.

"Word alignment has traditionally been studied between sentences, but many cross-lingual tasks increasingly require correspondences across full documents."

Evaluation Modes

partial

Automatic Metrics

Includes extracted eval setup.

"Word alignment has traditionally been studied between sentences, but many cross-lingual tasks increasingly require correspondences across full documents."

Quality Controls

missing

Not reported

No explicit QC controls found.

"Word alignment has traditionally been studied between sentences, but many cross-lingual tasks increasingly require correspondences across full documents."

Benchmarks / Datasets

missing

Not extracted

No benchmark anchors detected.

"Word alignment has traditionally been studied between sentences, but many cross-lingual tasks increasingly require correspondences across full documents."

Reported Metrics

partial

Error rate

Useful for evaluation criteria comparison.

"Averaged over three models, CTFAlign reduces word alignment error rate from 0.412 to 0.326."

Benchmarks and datasets

No benchmark or dataset names were extracted from the available abstract.

Reported metrics

error rate
Human feedback details
Uses human feedback
No
Feedback types
None
Rater population
Not reported
Expertise required
Coding, Multilingual
Evaluation details
Evaluation modes
Automatic Metrics
Agentic eval
None
Quality controls
Not reported
Evidence quality
Low
Use this page as
Background context only

Research brief

Metadata summary

Word alignment has traditionally been studied between sentences, but many cross-lingual tasks increasingly require correspondences across full documents.

Based on abstract + metadata only. Check the source paper before making high-confidence protocol decisions.

Key takeaways

  • Word alignment has traditionally been studied between sentences, but many cross-lingual tasks increasingly require correspondences across full documents.
  • While recent multilingual embedding models can encode long inputs, we show that applying algorithms designed for sentences directly to documents leads to performance degradation.
  • To address this, we introduce CTFAlign, a lightweight, training-free approach for document-level word alignment.

Researcher actions

  • Compare this paper against nearby papers in the same arXiv category before using it for protocol decisions.
  • Check the full text for explicit evaluation design choices (raters, protocol, and metrics).
  • Use related-paper links to find stronger protocol-specific references.

Caveats

  • Generated from abstract + metadata only; no PDF parsing.
  • Signals below are heuristic and may miss details reported outside the abstract.

Recommended queries

Contribution summary

  • While recent multilingual embedding models can encode long inputs, we show that applying algorithms designed for sentences directly to documents leads to performance degradation.
  • To address this, we introduce CTFAlign, a lightweight, training-free approach for document-level word alignment.
  • Additionally, we introduce MDPAlign, a simpler alternative that constrains alignments by position with a main diagonal prior.

Why it matters for eval

  • These gains transfer downstream, leading to improvements in document-level translation coverage evaluation and recognition of semantic differences.

Researcher checklist

  • Human feedback protocol is explicit

    No explicit human feedback protocol detected.

  • Evaluation mode is explicit

    Detected: Automatic Metrics

  • Quality control reporting appears

    No calibration/adjudication/IAA control explicitly detected.

  • Benchmark or dataset anchors are present

    No benchmark/dataset anchor extracted from abstract.

  • Metric reporting is present

    Detected: error rate