Compact Example-Based Explanations for Language Models

Loris Schoenegger, Benjamin Roth


Abstract
Training data influence estimation methods quantify the contribution of training documents to a model’s output, making them a promising source of information for example-based explanations.As humans cannot interpret thousands of documents, only a small subset of the training data can be presented as an explanation.Although the choice of which documents to include directly affects explanation quality, previous evaluations of such systems have largely ignored any selection strategies.To address this, we propose a novel *selection relevance score*, a retraining-free metric that quantifies how useful a set of examples is for explaining a model’s output.We validate this score through fine-tuning experiments, confirming that it can predict whether a set of examples supports or undermines the model’s predictions.Using this metric, we further show that common selection strategies often underperform random selection. Motivated by this finding, we propose a strategy that balances influence and representativeness, enabling better use of selection budgets than naively selecting the highest-ranking examples.
Anthology ID:
2026.findings-acl.1214
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
24246–24265
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URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1214/
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Cite (ACL):
Loris Schoenegger and Benjamin Roth. 2026. Compact Example-Based Explanations for Language Models. In Findings of the Association for Computational Linguistics: ACL 2026, pages 24246–24265, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Compact Example-Based Explanations for Language Models (Schoenegger & Roth, Findings 2026)
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1214.pdf
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