Diagnosing Vision-and-Language Navigation: What Really Matters

20971

Authors

nan

Abstract

AbstractVision-and-language navigation (VLN) is a multimodal task where an agent follows natural language instructions and navigates in visual environments. Multiple setups have been proposed, and researchers apply new model architectures or training techniques to boost navigation performance. However, there still exist non-negligible gaps between machines’ performance and human benchmarks. Moreover, the agents’ inner mechanisms for navigation decisions remain unclear. To the best of our knowledge, how the agents perceive the multimodal input is under-studied and needs investigation. In this work, we conduct a series of diagnostic experiments to unveil agents’ focus during navigation. Results show that indoor navigation agents refer to both object and direction tokens when making decisions. In contrast, outdoor navigation agents heavily rely on direction tokens and poorly understand the object tokens. Transformer-based agents acquire a better cross-modal understanding of objects and display strong numerical reasoning ability than non-Transformer-based agents. When it comes to vision-and-language alignments, many models claim that they can align object tokens with specific visual targets. We find unbalanced attention on the vision and text input and doubt the reliability of such cross-modal alignments.

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Proceedings of the 2022 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, pages 587 - 599 July 10-15, 2022 ©2022 Association for Computational Linguistics A Word is Worth A Thousand Dollars: Adversarial Attack on Tweets Fools Stock Prediction Yong Xie1, Dakuo Wang2,†, Pin-Yu Chen2, Jinjun Xiong3, Sijia Liu2,4 and Sanmi Koyejo1 1University of Illinois Urbana-Champaign, 2IBM 3State University of New York at Buffalo, 4Michigan State University Abstract More and more investors and machine learn- ing models rely on social media (e.g., Twit- ter and Reddit) to gather real-time informa- tion and sentiment to predict stock price move- ments. Although text-based models are known to be vulnerable to adversarial attacks, whether stock prediction models have similar vulnera- bility is underexplored. In this paper, we exper- iment with a variety of adversarial attack con- figurations to fool three stock prediction vic- tim models. We address the task of adversarial generation by solving combinatorial optimiza- tion problems with semantics and budget con- straints. Our results show that the proposed attack method can achieve consistent success rates and cause significant monetary loss in trading simulation by simply concatenating a perturbed but semantically similar tweet. 1 Introduction The advance of deep learning based language mod- els are playing a more and more important role in the financial context, including convolutional neutral network (CNN) (Ding et al., 2015), recur- rent neutral network (RNN) (Minh et al., 2018), long short-term memory network (LSTM) (Hiew et al., 2019; Sawhney et al., 2021; Hochreiter and Schmidhuber, 1997), graph neutral network (GNN) (Sawhney et al., 2020a,b), transformer (Yang et al., 2020), autoencoder (Xu and Cohen, 2018), etc. For example, Antweiler and Frank (2004) find that com- ments on Yahoo Finance can predict stock market volatility after controlling the effect of news. Cook- son and Niessner (2020) also show that sentiment disagreement on Stocktwits is highly related to cer- tain market activities. Readers can refer to these survey papers for more details (Dang et al., 2020; Zhang et al., 2018; Xing et al., 2018). † Corresponding author dakuo@acm.org. Our code is available at https://github.com/yonxie/ AdvFinTweet Figure 1: An example of word-replacement adversarial attack. (Top) benign tweet leads Stocknet to pre- dict stock going UP; (Bottom) adding an adversarial retweet leads Stocknet to predict stock going DOWN. It is now known that text-based deep learning models can be vulnerable to adversarial attacks (Szegedy et al., 2014; Goodfellow et al., 2015). The perturbation can be at the sentence level (e.g., Xu et al., 2021; Iyyer et al., 2018; Ribeiro et al., 2018), the word level (e.g., Zhang et al., 2019; Alzantot et al., 2018; Zang et al., 2020; Jin et al., 2020; Lei et al., 2019; Zhang et al., 2021; Lin et al., 2021), or both (Chen et al., 2021). We are interested in whether such adversarial attack vulnerability also exists in stock prediction models, as these models embrace more and more human-generated media data (e.g., Twitter, Reddit, Stocktwit, Yahoo News (Xu and Cohen, 2018; Sawhney …

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Labeled Text

AbstractVision-and-language navigation (VLN) is a multimodal task where an agent follows natural language instructions and navigates in visual environments. Multiple setups have been proposed, and researchers apply new model architectures or training techniques to boost navigation performance. However, there still exist non-negligible gaps between machines’ performance and human benchmarks. Moreover, the agents’ inner mechanisms for navigation decisions remain unclear. To the best of our knowledge, how the agents perceive the multimodal input is under-studied and needs investigation. In this work, we conduct a series of diagnostic experiments to unveil agents’ focus during navigation. Results show that indoor navigation agents refer to both object and direction tokens when making decisions. In contrast, outdoor navigation agents heavily rely on direction tokens and poorly understand the object tokens. Transformer-based agents acquire a better cross-modal understanding of objects and display strong numerical reasoning ability than non-Transformer-based agents. When it comes to vision-and-language alignments, many models claim that they can align object tokens with specific visual targets. We find unbalanced attention on the vision and text input and doubt the reliability of such cross-modal alignments.

Publication Details

Paper ID:
20971
Year:
2022
Publication:
TIPSTER
Publication Type:
conf
DOI:
nan