Anubhav Sinha


2024

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Why Generate When You Can Discriminate? A Novel Technique for Text Classification using Language Models
Sachin Pawar | Nitin Ramrakhiyani | Anubhav Sinha | Manoj Apte | Girish Palshikar
Findings of the Association for Computational Linguistics: EACL 2024

In this paper, we propose a novel two-step technique for text classification using autoregressive Language Models (LM). In the first step, a set of perplexity and log-likelihood based numeric features are elicited from an LM for a text instance to be classified. Then, in the second step, a classifier based on these features is trained to predict the final label. The classifier used is usually a simple machine learning classifier like Support Vector Machine (SVM) or Logistic Regression (LR) and it is trained using a small set of training examples. We believe, our technique presents a whole new way of exploiting the available training instances, in addition to the existing ways like fine-tuning LMs or in-context learning. Our approach stands out by eliminating the need for parameter updates in LMs, as required in fine-tuning, and does not impose limitations on the number of training examples faced while building prompts for in-context learning. We evaluate our technique across 5 different datasets and compare with multiple competent baselines.

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Unintended Bias Detection and Mitigation in Misogynous Memes
Gitanjali Kumari | Anubhav Sinha | Asif Ekbal
Proceedings of the 18th Conference of the European Chapter of the Association for Computational Linguistics (Volume 1: Long Papers)

Online sexism has become a concerning issue in recent years, especially conveyed through memes. Although this alarming phenomenon has triggered many studies from computational linguistic and natural language processing points of view, less effort has been spent analyzing if those misogyny detection models are affected by an unintended bias. Such biases can lead models to incorrectly label non-misogynous memes misogynous due to specific identity terms, perpetuating harmful stereotypes and reinforcing negative attitudes. This paper presents the first and most comprehensive approach to measure and mitigate unintentional bias in the misogynous memes detection model, aiming to develop effective strategies to counter their harmful impact. Our proposed model, the Contextualized Scene Graph-based Multimodal Network (CTXSGMNet), is an integrated architecture that combines VisualBERT, a CLIP-LSTM-based memory network, and an unbiased scene graph module with supervised contrastive loss, achieves state-of-the-art performance in mitigating unintentional bias in misogynous memes.Empirical evaluation, including both qualitative and quantitative analysis, demonstrates the effectiveness of our CTXSGMNet framework on the SemEval-2022 Task 5 (MAMI task) dataset, showcasing its promising performance in terms of Equity of Odds and F1 score. Additionally, we assess the generalizability of the proposed model by evaluating their performance on a few benchmark meme datasets, providing a comprehensive understanding of our approach’s efficacy across diverse datasets.