Spot the BlindSpots: Systematic Identification and Quantification of Fine-Grained LLM Biases in Contact Center Call Summarization

Kawin Mayilvaghanan, Siddhant Gupta, Ayush Kumar


Abstract
Abstractive summarization is a core application in contact centers, where Large Language Models (LLMs) generate millions of summaries of call transcripts daily. Despite their apparent quality, it remains unclear whether LLMs systematically under- or over-attend to specific aspects of the transcript, potentially introducing biases in the generated summary. While prior work has examined social and positional biases, the specific forms of bias pertinent to contact center operations—which we term ‘Operational Bias’—have remained unexplored. To address this gap, we introduce BlindSpot, a framework built upon a taxonomy of 15 operational bias dimensions (e.g., disfluency, speaker, topic) for the identification and quantification of these biases. BlindSpot leverages an LLM as a zero-shot classifier to derive categorical distributions for each bias dimension in a pair of transcript and its summary. The bias is then quantified using two metrics: Fidelity Gap, measured as the Total Variation Distance (TVD) between distributions, and Coverage, defined as the percentage of source labels omitted. Using BlindSpot, we conduct an empirical study with 2500 real call transcripts and their summaries generated by 20 LLMs of varying scales and families (e.g., GPT, Llama, Claude). Our analysis reveals that biases are systemic and present across all evaluated models, regardless of size or family. We further report on bias mitigation via targeted prompting which measurably reduces bias across models.
Anthology ID:
2025.emnlp-industry.91
Volume:
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing: Industry Track
Month:
November
Year:
2025
Address:
Suzhou (China)
Editors:
Saloni Potdar, Lina Rojas-Barahona, Sebastien Montella
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
1299–1340
Language:
URL:
https://preview.aclanthology.org/ingest-emnlp/2025.emnlp-industry.91/
DOI:
Bibkey:
Cite (ACL):
Kawin Mayilvaghanan, Siddhant Gupta, and Ayush Kumar. 2025. Spot the BlindSpots: Systematic Identification and Quantification of Fine-Grained LLM Biases in Contact Center Call Summarization. In Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing: Industry Track, pages 1299–1340, Suzhou (China). Association for Computational Linguistics.
Cite (Informal):
Spot the BlindSpots: Systematic Identification and Quantification of Fine-Grained LLM Biases in Contact Center Call Summarization (Mayilvaghanan et al., EMNLP 2025)
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https://preview.aclanthology.org/ingest-emnlp/2025.emnlp-industry.91.pdf