Payel Santra

I am a Senior Research Fellow (PhD candidate) at the Indian Association for the Cultivation of Science (IACS), Kolkata, in the School of Mathematical and Computational Sciences (Computer Science Unit), under the supervision of Dr. Partha Basuchowdhuri.

My research focuses on building reliable and adaptive retrieval-centric systems in Information Retrieval (IR) and Natural Language Processing (NLP). I am interested in understanding how retrieval and generation decisions should be made at a per-query level, and how these principles can be applied to reliability-critical NLP tasks.

My work spans three key directions:

  • Query-Adaptive RAG Designing retrieval-augmented generation systems that adapt retriever, corpus, and generation choices per query, recognizing that no single configuration is optimal across varying information needs, ambiguity, and evidence redundancy.
  • QPP Extending Query Performance Prediction to multi-ranker and stochastic settings to enable per-query selection, fusion, and robustness in retrieval and LLM-driven ranking systems.
  • Reliability-Aware NLP Developing unsupervised and weakly supervised methods for fact verification and correction, emphasizing evidence quality, minimal edits, and generalizable architectures.

My curriculum vitae is available here.

[Google Scholar] [GitHub] [LinkedIn] [Email]

News

Publications

I have authored papers published in proceedings/journals including ACL, SIGIR, CIKM, ECIR, WIREs, DaWaK, and AACL-IJCNLP.

  1. Mask-to-Correct+: Leveraging Retriever Diversity for Masking-guided Faithful Fact Correction
    Payel Santra, Lavisha Sharma, Madhusudan Ghosh, and Partha Basuchowdhuri
    ACL 2026 The 64th Annual Meeting of the Association for Computational Linguistics (Long Paper), San Diego, California, July 2026
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  2. Breaking Flat: A Generalised Query Performance Prediction Evaluation Framework
    Payel Santra, Partha Basuchowdhuri, and Debasis Ganguly
    ECIR 2026 Advances in Information Retrieval – 48th European Conference on Information Retrieval, Delft, The Netherlands, March–April 2026. Springer
  3. Beyond Correlations: A Downstream Evaluation Framework for Query Performance Prediction
    Payel Santra, Partha Basuchowdhuri, and Debasis Ganguly
    ECIR 2026 Advances in Information Retrieval – 48th European Conference on Information Retrieval, Delft, The Netherlands, March–April 2026. Springer
  4. HF-RAG: Hierarchical Fusion-based RAG with Multiple Sources and Rankers
    Payel Santra, Madhusudan Ghosh, Debasis Ganguly, Partha Basuchowdhuri, and Sudip Kumar Naskar
    CIKM 2025 Proceedings of the 34th ACM International Conference on Information and Knowledge Management. ACM, 2025
  5. The "Curious Case of Contexts" in Retrieval-Augmented Generation With a Combination of Labeled and Unlabeled Data
    Payel Santra, Madhusudan Ghosh, Debasis Ganguly, Partha Basuchowdhuri, and Sudip Kumar Naskar
    Journal Wiley Interdisciplinary Reviews: Data Mining and Knowledge Discovery, 15(2):e70021, 2025
  6. "The Absence of Evidence is Not the Evidence of Absence": Fact Verification via Information Retrieval-Based In-Context Learning
    Payel Santra, Madhusudan Ghosh, Debasis Ganguly, Partha Basuchowdhuri, and Sudip Kumar Naskar
    DaWaK 2024 International Conference on Big Data Analytics and Knowledge Discovery, pages 381–387. Springer, 2024
  7. Leveraging LLMs for Detecting and Modeling the Propagation of Misinformation in Social Networks
    Payel Santra
    SIGIR 2024 Proceedings of the 47th International ACM SIGIR Conference on Research and Development in Information Retrieval, pages 3073–3073, 2024 (Doctoral Consortium)
  8. BLINKLSTM: Bio Link BERT and LSTM based approach for extraction of PICO frame from Clinical Trial Text
    Madhusudan Ghosh, Shrimon Mukherjee, Payel Santra, Girish, and Partha Basuchowdhuri
    CODS-COMAD 2024 7th International Conference on Data Science and Management of Data, IIIT Bangalore, January 2024
  9. Unleashing the Power of Large Language Models: A Hands-On Tutorial
    Payel Santra, Madhusudan Ghosh, Shrimon Mukherjee, Debasis Ganguly, Partha Basuchowdhuri, and Sudip Kumar Naskar
    FIRE 2023 15th Annual Meeting of the Forum for Information Retrieval Evaluation, Goa University, India, December 2023
  10. Analyzing the Efficacy of LLM-Generated Evidences for Fact Verification: An In-depth Analysis
    Payel Santra, Madhusudan Ghosh, Debasis Ganguly, Partha Basuchowdhuri, and Sudip Kumar Naskar
    LLMIT@CIKM 2023 1st Workshop on Large Language Models' Interpretability and Trustworthiness, University of Birmingham & Eastside Rooms, UK, October 2023
  11. Astro-mT5: Entity Extraction from Astrophysics Literature using mT5 Language Model
    Madhusudan Ghosh, Payel Santra, Sk Asif Iqbal, and Partha Basuchowdhuri
    AACL-IJCNLP 2022 1st Workshop on Information Extraction from Scientific Publications, Taipei, Taiwan, November 2022. ACL

Teaching & Supervision

Tutorials Presented

  • Unleashing the Power of Large Language Models: A Hands-On Tutorial. Payel Santra, Madhusudan Ghosh, Shrimon Mukherjee, Debasis Ganguly, Partha Basuchowdhuri, Sudip Kumar Naskar. FIRE 2023, Goa University, India.
  • Introduction to Machine Learning and Deep Learning. Payel Santra, Madhusudan Ghosh, Sudip Kumar Naskar. Calcutta Electric Supply Corporation Limited (CESC), Kolkata, 2024.

Teaching Assistantship — IACS, Kolkata

  • MCS 2101B: Data Structures & Algorithms (Autumn Semester 2023)
  • COM 5203: Social and Complex Networks (Spring Semester 2023)
  • COM 1101: Introduction to Computing (Autumn Semester 2024)

PhD Mentorship (2024)

  • Jiajie Chen, University of Glasgow (with Dr. Debasis Ganguly)
  • Lavisha Sharma, IACS, Kolkata (with Dr. Partha Basuchowdhuri)
  • V. Shanmukha Sai, IIIT Dharwar (SRFP Fellow)
  • Yucong Lai, University of Glasgow (with Dr. Debasis Ganguly)

Achievements & Honors

Education

Sep 2021 – Present
PhD in Computer Science (Pursuing)
Indian Association for the Cultivation of Science (IACS), Kolkata, India
Thesis: Bridging the Gap between Misinformation and Correction using Multimodal Neural Networks
Advisor: Dr. Partha Basuchowdhuri  |  CGPA: 9.0 / 10
2019 – 2021
Bachelor of Education (B.Ed)
Govt. College of Education, University of Burdwan, Burdwan, India
CGPA: 9.09 / 10
2017 – 2019
M.Sc. in Applied Mathematics
Indian Institute of Engineering Science and Technology, Shibpur (IIEST), Kolkata, India
Percentage: 93.4%
2014 – 2017
B.Sc. (Hons.) in Mathematics
University of Burdwan (Chandernagore College), Hooghly, India
Percentage: 75.0%

Skills

Programming

PythonCJavaFORTRAN

ML / DL Frameworks

PyTorchTensorFlowKeras

IR & NLP Tools

PyseriniLuceneSpaCyStanzaStanford Parsers

Visualization & Analysis

MatplotlibSeabornt-SNENetworkXGephi

Scientific Computing

MathematicaNumPy

Research Domains

RAGLLMsQPPFact VerificationMathematical BiologyEpidemiology

Contact

Payel Santra
Senior Research Fellow
Computer Science Unit, Lab Room No. 401, TRC Building
School of Mathematical and Computational Sciences
Indian Association for the Cultivation of Science
Jadavpur, Kolkata – 700032, India

📧 payel.iacs@gmail.com

References

Dr. Partha Basuchowdhuri
Assistant Professor, CS Unit
IACS, Kolkata
partha.basuchowdhuri@iacs.res.in
Dr. Debasis Ganguly
Assistant Professor, School of Computing
University of Glasgow
Debasis.Ganguly@glasgow.ac.uk
Dr. Sudip Kumar Naskar
Associate Professor, Dept. of CSE
Jadavpur University, Kolkata
sudipkumar.naskar@jadavpuruniversity.in