Machine Translation Digest for Oct 27 2026
ETC-Bench covers 181 phenomenon types across 12 languages, giving transcript canonicalization a much more explicit testbed than the usual ad hoc normalization setups. Alongside it, one paper proposes a perturbation-based way to detect input ambiguity in LLMs before a model has a chance to “helpfully” disambiguate the prompt, and another adapts explainability methods and evaluation metrics to multimodal document understanding, where layout, text and visual structure all matter.
DocXEval: A Systematic Evaluation of Explainability in Multimodal Document Understanding
For document QA and extraction pipelines, Occlusion is the most faithful and interpretable XAI method overall, while only a few of 13 methods stay reliable across 17 metrics on 8 datasets.
Multimodal transformer models have driven unprecedented performance breakthroughs in modern document understanding. However, the inherent black-box nature of these models remains a major obstacle to their safe deployment in high-stakes sectors. Despite significant progress in explainability for vision and language tasks, explainable AI (XAI) research tailored to multimodal document understanding has received little attention. To address this gap, we present , the first comprehensive explainability framework that adapts existing XAI methods and evaluation metrics to the multimodal (text, layout, and image) document understanding context, while introducing efficient multi-target adaptations of both methods and metrics for domain-specific tasks such as semantic entity recognition. Using , we systematically evaluate 13 XAI methods across 3 document understanding tasks, 8 datasets, 4 models, and 17 evaluation metrics, and find that only a few methods perform consistently across all evaluation criteria, with Occlusion emerging as the most faithful and interpretable method overall. Through a dedicated meta-evaluation, we observe moderate to strong agreement among several faithfulness and complexity metrics while identifying certain ones that produce unreliable results. Finally, through multiple dataset-wide diagnostic analyses, we uncover key insights into model behavior, including the contribution of individual modalities across tasks and labels, spatial attribution patterns around target entities, and potential dataset biases. Overall, this work serves as both a benchmark and a practical guide for future XAI research in multimodal document understanding. To support reproducibility, we publicly release our code at https://github.com/saifullah3396/docxeval/.
Detect Before You Disambiguate: Perturbation-Based Input Ambiguity Detection in LLMs
Ambiguity detection should happen before disambiguation: label-preserving perturbations beat output-side uncertainty and LLM-paraphrase baselines across four QA datasets.
Large language models (LLMs) often answer ambiguous inputs as if they had a single intended meaning. This is problematic because input ambiguity is an upstream source of uncertainty: when a prompt admits multiple valid interpretations, the key question is whether the model should answer directly at all. Existing input uncertainty methods often rely on LLM-generated statements or clarifications, but such transformations may already disambiguate the input before the ambiguity is measured. We propose a label-preserving perturbation framework for input ambiguity detection in which perturbations remain close to the original input while preserving its label. We instantiate this principle with two detectors: a black-box rule-based perturbation library and a white-box importance-guided method using model-internal signals. Experiments across four datasets in open-domain, conversational, and visual QA show that our methods outperform output-side uncertainty baselines and LLM-paraphrase-based perturbation baselines. Our results highlight the importance of detecting ambiguity before attempting to disambiguate it. Our code is available ://github.com/Xiao0o0o/input-ambiguity-detection{ }.
ETC-Bench: A Multilingual Benchmark for Evaluation-Side Transcript Canonicalization
For speech transcripts, canonicalization needs evaluation that preserves meaning: ETC-Bench covers 181 phenomena in 12 languages, and SENA penalises exact-match fixes that change semantics.
Written transcripts of the same speech can differ in ways that are not uniquely determined by the speech signal. We formulate evaluation-side transcript canonicalization (ETC), which maps multiple surface forms to a single canonical form when their differences are not determined by speech. To our knowledge, ETC-Bench is the first and most comprehensive multilingual benchmark for evaluation-side transcript canonicalization, covering 181 phenomenon types across 12 languages. Each instance is a minimal pair that shares a sentence context and differs only in a target span exhibiting one phenomenon. To evaluate both canonicalization success and semantic preservation, we propose Semantic-preserving Exact-match Normalization Accuracy (SENA), which combines exact agreement between independently canonicalized pair members with a pair-relative BERTScore constraint against information loss. We further introduce the Taxonomy-guided Agent Canonicalization Skill (TACS), which provides LLM agents with phenomenon descriptions and explicit canonicalization contracts. Experiments with five baseline configurations and three TACS-based agents show that the agents outperform the baseline systems on shared languages. ETC-Bench provides a systematic testbed for evaluation-side transcript canonicalization across languages.
Papers announced by arXiv on Tuesday, 27 October 2026, covering submissions from 26 October to 27 October 2026.