Siva Rajesh Kasa


2025

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Generative or Discriminative? Revisiting Text Classification in the Era of Transformers
Siva Rajesh Kasa | Karan Gupta | Sumegh Roychowdhury | Ashutosh Kumar | Yaswanth Biruduraju | Santhosh Kumar Kasa | Pattisapu Nikhil Priyatam | Arindam Bhattacharya | Shailendra Agarwal | Vijay Huddar
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing

*The comparison between discriminative and generative classifiers has intrigued researchers since [Efron (1975)’s](https://www.jstor.org/stable/2285453) seminal analysis of logistic regression versus discriminant analysis. While early theoretical work established that generative classifiers exhibit lower sample complexity but higher asymptotic error in simple linear settings, these trade-offs remain unexplored in the transformer era. We present the first comprehensive evaluation of modern generative and discriminative architectures—Auto-regressive, Masked Language Modeling, Discrete Diffusion, and Encoders for text classification. Our study reveals that the classical “two regimes” phenomenon manifests distinctly across different architectures and training paradigms. Beyond accuracy, we analyze sample efficiency, calibration, noise robustness, and ordinality across diverse scenarios. Our findings offer practical guidance for selecting the most suitable modeling approach based on real-world constraints such as latency and data limitations.*

2024

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Exploring Ordinality in Text Classification: A Comparative Study of Explicit and Implicit Techniques
Siva Rajesh Kasa | Aniket Goel | Karan Gupta | Sumegh Roychowdhury | Pattisapu Priyatam | Anish Bhanushali | Prasanna Srinivasa Murthy
Findings of the Association for Computational Linguistics: ACL 2024

Ordinal Classification (OC) is a widely encountered challenge in Natural Language Processing (NLP), with applications in various domains such as sentiment analysis, rating prediction, and more. Previous approaches to tackle OC have primarily focused on modifying existing or creating novel loss functions that explicitly account for the ordinal nature of labels. However, with the advent of Pre-trained Language Models (PLMs), it became possible to tackle ordinality through the implicit semantics of the labels as well. This paper provides a comprehensive theoretical and empirical examination of both these approaches. Furthermore, we also offer strategic recommendations regarding the most effective approach to adopt based on specific settings.