Orestis Papakyriakopoulos


2024

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Resampled Datasets Are Not Enough: Mitigating Societal Bias Beyond Single Attributes
Yusuke Hirota | Jerone Andrews | Dora Zhao | Orestis Papakyriakopoulos | Apostolos Modas | Yuta Nakashima | Alice Xiang
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing

We tackle societal bias in image-text datasets by removing spurious correlations between protected groups and image attributes. Traditional methods only target labeled attributes, ignoring biases from unlabeled ones. Using text-guided inpainting models, our approach ensures protected group independence from all attributes and mitigates inpainting biases through data filtering. Evaluations on multi-label image classification and image captioning tasks show our method effectively reduces bias without compromising performance across various models. Specifically, we achieve an average societal bias reduction of 46.1% in leakage-based bias metrics for multi-label classification and 74.8% for image captioning.

2020

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NLP-based Feature Extraction for the Detection of COVID-19 Misinformation Videos on YouTube
Juan Carlos Medina Serrano | Orestis Papakyriakopoulos | Simon Hegelich
Proceedings of the 1st Workshop on NLP for COVID-19 at ACL 2020

We present a simple NLP methodology for detecting COVID-19 misinformation videos on YouTube by leveraging user comments. We use transfer learning pre-trained models to generate a multi-label classifier that can categorize conspiratorial content. We use the percentage of misinformation comments on each video as a new feature for video classification.