Adversarial Regularization for Visual Question Answering: Strengths, Shortcomings, and Side Effects

Gabriel Grand, Yonatan Belinkov


Abstract
Visual question answering (VQA) models have been shown to over-rely on linguistic biases in VQA datasets, answering questions “blindly” without considering visual context. Adversarial regularization (AdvReg) aims to address this issue via an adversary sub-network that encourages the main model to learn a bias-free representation of the question. In this work, we investigate the strengths and shortcomings of AdvReg with the goal of better understanding how it affects inference in VQA models. Despite achieving a new state-of-the-art on VQA-CP, we find that AdvReg yields several undesirable side-effects, including unstable gradients and sharply reduced performance on in-domain examples. We demonstrate that gradual introduction of regularization during training helps to alleviate, but not completely solve, these issues. Through error analyses, we observe that AdvReg improves generalization to binary questions, but impairs performance on questions with heterogeneous answer distributions. Qualitatively, we also find that regularized models tend to over-rely on visual features, while ignoring important linguistic cues in the question. Our results suggest that AdvReg requires further refinement before it can be considered a viable bias mitigation technique for VQA.
Anthology ID:
W19-1801
Volume:
Proceedings of the Second Workshop on Shortcomings in Vision and Language
Month:
June
Year:
2019
Address:
Minneapolis, Minnesota
Venues:
NAACL | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
1–13
Language:
URL:
https://aclanthology.org/W19-1801
DOI:
10.18653/v1/W19-1801
Bibkey:
Cite (ACL):
Gabriel Grand and Yonatan Belinkov. 2019. Adversarial Regularization for Visual Question Answering: Strengths, Shortcomings, and Side Effects. In Proceedings of the Second Workshop on Shortcomings in Vision and Language, pages 1–13, Minneapolis, Minnesota. Association for Computational Linguistics.
Cite (Informal):
Adversarial Regularization for Visual Question Answering: Strengths, Shortcomings, and Side Effects (Grand & Belinkov, 2019)
Copy Citation:
PDF:
https://aclanthology.org/W19-1801.pdf
Code
 gabegrand/adversarial-vqa
Data
Visual Question AnsweringVisual Question Answering v2.0