Publications

Total pubs: 32

2022

  1. Ray Choudhury, S., Rogers, A., & Augenstein, I. (2022). Machine Reading, Fast and Slow: When Do Models “Understand” Language? Proceedings of the 29th International Conference on Computational Linguistics, 78–93. Gyeongju, Republic of Korea: International Committee on Computational Linguistics.
    Two of the most fundamental issues in Natural Language Understanding (NLU) at present are: (a) how it can established whether deep learning-based models score highly on NLU benchmarks for the ”right” reasons; and (b) what those reasons would even be. We investigate the behavior of reading comprehension models with respect to two linguistic ”skills”: coreference resolution and comparison. We propose a definition for the reasoning steps expected from a system that would be ”reading slowly”, and compare that with the behavior of five models of the BERT family of various sizes, observed through saliency scores and counterfactual explanations. We find that for comparison (but not coreference) the systems based on larger encoders are more likely to rely on the ”right” information, but even they struggle with generalization, suggesting that they still learn specific lexical patterns rather than the general principles of comparison.
  2. Thorn Jakobsen, T., & Rogers, A. (2022). What Factors Should Paper-Reviewer Assignments Rely On? Community Perspectives on Issues and Ideals in Conference Peer-Review. Proceedings of the 2022 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, 4810–4823. Seattle, United States: Association for Computational Linguistics.
    Both scientific progress and individual researcher careers depend on the quality of peer review, which in turn depends on paper-reviewer matching. Surprisingly, this problem has been mostly approached as an automated recommendation problem rather than as a matter where different stakeholders (area chairs, reviewers, authors) have accumulated experience worth taking into account. We present the results of the first survey of the NLP community, identifying common issues and perspectives on what factors should be considered by paper-reviewer matching systems. This study contributes actionable recommendations for improving future NLP conferences, and desiderata for interpretable peer review assignments.
  3. Puccetti, G., Rogers, A., Drozd, A., & Dell’Orletta, F. (2022). Outliers Dimensions that Disrupt Transformers Are Driven by Frequency. Findings of EMNLP 2022 (to appear). https://doi.org/10.48550/ARXIV.2205.11380
    Transformer-based language models are known to display anisotropic behavior: the token embeddings are not homogeneously spread in space, but rather accumulate along certain directions. A related recent finding is the outlier phenomenon: the parameters in the final element of Transformer layers that consistently have unusual magnitude in the same dimension across the model, and significantly degrade its performance if disabled. We replicate the evidence for the outlier phenomenon and we link it to the geometry of the embedding space. Our main finding is that in both BERT and RoBERTa the token frequency, known to contribute to anisotropicity, also contributes to the outlier phenomenon. In its turn, the outlier phenomenon contributes to the "vertical" self-attention pattern that enables the model to focus on the special tokens. We also find that, surprisingly, the outlier effect on the model performance varies by layer, and that variance is also related to the correlation between outlier magnitude and encoded token frequency.
  4. Laurençon, H., Saulnier, L., Wang, T., Akiki, C., del Moral, A. V., Scao, T. L., … Jernite, Y. (2022). The BigScience ROOTS Corpus: A 1.6TB Composite Multilingual Dataset. Thirty-sixth Conference on Neural Information Processing Systems Datasets and Benchmarks Track.
  5. Jernite, Y., Nguyen, H., Biderman, S., Rogers, A., Masoud, M., Danchev, V., … Mitchell, M. (2022). Data Governance in the Age of Large-Scale Data-Driven Language Technology. 2022 ACM Conference on Fairness, Accountability, and Transparency, 2206–2222. https://doi.org/10.1145/3531146.3534637
    The recent emergence and adoption of Machine Learning technology, and specifically of Large Language Models, has drawn attention to the need for systematic and transparent management of language data. This work proposes an approach to global language data governance that attempts to organize data management amongst stakeholders, values, and rights. Our proposal is informed by prior work on distributed governance that accounts for human values and grounded by an international research collaboration that brings together researchers and practitioners from 60 countries. The framework we present is a multi-party international governance structure focused on language data, and incorporating technical and organizational tools needed to support its work.
  6. Rogers, A., Gardner, M., & Augenstein, I. (2022). QA Dataset Explosion: A Taxonomy of NLP Resources for Question Answering and Reading Comprehension. ACM CSUR. https://doi.org/https://doi.org/10.1145/3560260
    Alongside huge volumes of research on deep learning models in NLP in the recent years, there has been also much work on benchmark datasets needed to track modeling progress. Question answering and reading comprehension have been particularly prolific in this regard, with over 80 new datasets appearing in the past two years. This study is the largest survey of the field to date. We provide an overview of the various formats and domains of the current resources, highlighting the current lacunae for future work. We further discuss the current classifications of “reasoning types" in question answering and propose a new taxonomy. We also discuss the implications of over-focusing on English, and survey the current monolingual resources for other languages and multilingual resources. The study is aimed at both practitioners looking for pointers to the wealth of existing data, and at researchers working on new resources.

2021

  1. Bhargava, P., Drozd, A., & Rogers, A. (2021). Generalization in NLI: Ways (Not) To Go Beyond Simple Heuristics. Proceedings of the Second Workshop on Insights from Negative Results in NLP, 125–135. Online and Punta Cana, Dominican Republic: Association for Computational Linguistics.
    Much of recent progress in NLU was shown to be due to models’ learning dataset-specific heuristics. We conduct a case study of generalization in NLI (from MNLI to the adversarially constructed HANS dataset) in a range of BERT-based architectures (adapters, Siamese Transformers, HEX debiasing), as well as with subsampling the data and increasing the model size. We report 2 successful and 3 unsuccessful strategies, all providing insights into how Transformer-based models learn to generalize.
  2. González, A. V., Rogers, A., & Søgaard, A. (2021). On the Interaction of Belief Bias and Explanations. Findings of ACL-IJCNLP 2021, 2930–2942. Online: ACL.
    A myriad of explainability methods have been proposed in recent years, but there is little consensus on how to evaluate them. While automatic metrics allow for quick benchmarking, it isn’t clear how such metrics reflect human interaction with explanations. Human evaluation is of paramount importance, but previous protocols fail to account for belief biases affecting human performance, which may lead to misleading conclusions. We provide an overview of belief bias, its role in human evaluation, and ideas for NLP practitioners on how to account for it. For two experimental paradigms, we present a case study of gradient-based explainability introducing simple ways to account for humans’ prior beliefs: models of varying quality and adversarial examples. We show that conclusions about the highest performing methods change when introducing such controls, pointing to the importance of accounting for belief bias in evaluation.
  3. Kovaleva, O., Kulshreshtha, S., Rogers, A., & Rumshisky, A. (2021). BERT Busters: Outlier Dimensions That Disrupt Transformers. Findings of ACL-IJCNLP 2021, 3392–3405. Online: ACL.
    Multiple studies have shown that Transformers are remarkably robust to pruning. Contrary to this received wisdom, we demonstrate that pre-trained Transformer encoders are surprisingly fragile to the removal of a very small number of features in the layer outputs (<0.0001% of model weights). In case of BERT and other pre-trained encoder Transformers, the affected component is the scaling factors and biases in the LayerNorm. The outliers are high-magnitude normalization parameters that emerge early in pre-training and show up consistently in the same dimensional position throughout the model. We show that disabling them significantly degrades both the MLM loss and the downstream task performance. This effect is observed across several BERT-family models and other popular pre-trained Transformer architectures, including BART, XLNet and ELECTRA; we also show a similar effect in GPT-2.
  4. Rogers, A. (2021). Changing the World by Changing the Data. Proceedings of the 59th Annual Meeting of the Association for Computational Linguistics and the 11th International Joint Conference on Natural Language Processing (Volume 1: Long Papers), 2182–2194. Online: ACL.
    NLP community is currently investing a lot more research and resources into development of deep learning models than training data. While we have made a lot of progress, it is now clear that our models learn all kinds of spurious patterns, social biases, and annotation artifacts. Algorithmic solutions have so far had limited success. An alternative that is being actively discussed is more careful design of datasets so as to deliver specific signals. This position paper maps out the arguments for and against data curation, and argues that fundamentally the point is moot: curation already is and will be happening, and it is changing the world. The question is only how much thought we want to invest into that process.

2020

  1. Rogers, A., & Augenstein, I. (2020). What Can We Do to Improve Peer Review in NLP? Findings of EMNLP, 1256–1262. Online: ACL.
  2. Prasanna, S., Rogers, A., & Rumshisky, A. (2020). When BERT Plays the Lottery, All Tickets Are Winning. Proceedings of EMNLP, 3208–3229. Online: ACL.
    Much of the recent success in NLP is due to the large Transformer-based models such as BERT (Devlin et al, 2019). However, these models have been shown to be reducible to a smaller number of self-attention heads and layers. We consider this phenomenon from the perspective of the lottery ticket hypothesis. For fine-tuned BERT, we show that (a) it is possible to find a subnetwork of elements that achieves performance comparable with that of the full model, and (b) similarly-sized subnetworks sampled from the rest of the model perform worse. However, the "bad" subnetworks can be fine-tuned separately to achieve only slightly worse performance than the "good" ones, indicating that most weights in the pre-trained BERT are potentially useful. We also show that the "good" subnetworks vary considerably across GLUE tasks, opening up the possibilities to learn what knowledge BERT actually uses at inference time.
  3. Rogers, A., Kovaleva, O., Downey, M., & Rumshisky, A. (2020). Getting Closer to AI Complete Question Answering: A Set of Prerequisite Real Tasks. Proceedings of the AAAI Conference on Artificial Intelligence, 11.
    The recent explosion in question answering research produced a wealth of both factoid RC and commonsense reasoning datasets. Combining them presents a different kind of task: not deciding simply whether information is present in the text, but also whether a confident guess could be made for the missing information. To that end, we present QuAIL, the first reading comprehension dataset (a) to combine textbased, world knowledge and unanswerable questions, and (b) to provide annotation that would enable precise diagnostics of the reasoning strategies by a given QA system. QuAIL contains 15K multi-choice questions for 800 texts in 4 domains (fiction, blogs, political news, and user story texts). Crucially, to solve QuAIL a system would need to handle both general and text-specific questions, impossible to answer from pretraining data. We show that the new benchmark poses substantial challenges to the current state-of-the-art systems, with a 30% drop in accuracy compared to the most similar existing dataset.
  4. Rogers, A., Kovaleva, O., & Rumshisky, A. (2020). A Primer in BERTology: What We Know About How BERT Works. Transactions of the Association for Computational Linguistics, 8, 842–866.
    Transformer-based models have pushed state of the art in many areas of NLP, but our understanding of what is behind their success is still limited. This paper is the first survey of over 150 studies of the popular BERT model. We review the current state of knowledge about how BERT works, what kind of information it learns and how it is represented, common modifications to its training objectives and architecture, the overparameterization issue, and approaches to compression. We then outline directions for future research.

2019

  1. Kovaleva, O., Romanov, A., Rogers, A., & Rumshisky, A. (2019). Revealing the Dark Secrets of BERT. Proceedings of EMNLP-IJCNLP), 4356–4365. https://doi.org/10.18653/v1/D19-1445
    BERT-based architectures currently give state-of-the-art performance on many NLP tasks, but little is known about the exact mechanisms that contribute to its success. In the current work, we focus on the interpretation of self-attention, which is one of the fundamental underlying components of BERT. Using a subset of GLUE tasks and a set of handcrafted features-of-interest, we propose the methodology and carry out a qualitative and quantitative analysis of the information encoded by the individual BERT’s heads. Our findings suggest that there is a limited set of attention patterns that are repeated across different heads, indicating the overall model overparametrization. While different heads consistently use the same attention patterns, they have varying impact on performance across different tasks. We show that manually disabling attention in certain heads leads to a performance improvement over the regular fine-tuned BERT models.
  2. Rogers, A., Drozd, A., Rumshisky, A., & Goldberg, Y. (2019). Proceedings of the 3rd Workshop on Evaluating Vector Space Representations for NLP.
  3. Rogers, A., Kovaleva, O., & Rumshisky, A. (2019). Calls to Action on Social Media: Potential for Censorship and Social Impact. EMNLP-IJCNLP 2019 Second Workshop on Natural Language Processing for Internet Freedom.
  4. Rogers, A., Smelkov, G., & Rumshisky, A. (2019). NarrativeTime: Dense High-Speed Temporal Annotation on a Timeline. ArXiv:1908.11443 [Cs].
    We present NarrativeTime, a new timeline-based annotation scheme for temporal order of events in text, and a new densely annotated fiction corpus comparable to TimeBank-Dense. NarrativeTime is considerably faster than schemes based on event pairs such as TimeML, and it produces more temporal links between events than TimeBank-Dense, while maintaining comparable agreement on temporal links. This is achieved through new strategies for encoding vagueness in temporal relations and an annotation workflow that takes into account the annotators’ chunking and commonsense reasoning strategies. NarrativeTime comes with new specialized web-based tools for annotation and adjudication.
  5. Romanov, A., Rumshisky, A., Rogers, A., & Donahue, D. (2019). Adversarial Decomposition of Text Representation. Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers), 815–825.

2018

  1. Karpinska, M., Li, B., Rogers, A., & Drozd, A. (2018). Subcharacter Information in Japanese Embeddings: When Is It Worth It? Proceedings of the Workshop on the Relevance of Linguistic Structure in Neural Architectures for NLP, 28–37. Melbourne, Australia: ACL.
  2. Rogers, A., Hosur Ananthakrishna, S., & Rumshisky, A. (2018). What’s in Your Embedding, And How It Predicts Task Performance. Proceedings of the 27th International Conference on Computational Linguistics, 2690–2703. Santa Fe, New Mexico, USA, August 20-26, 2018: ACL.
  3. Rogers, A., Romanov, A., Rumshisky, A., Volkova, S., Gronas, M., & Gribov, A. (2018). RuSentiment: An Enriched Sentiment Analysis Dataset for Social Media in Russian. Proceedings of the 27th International Conference on Computational Linguistics, 755–763. Santa Fe, New Mexico, USA: ACL.

2017

  1. Li, B., Liu, T., Zhao, Z., Tang, B., Drozd, A., Rogers, A., & Du, X. (2017). Investigating Different Syntactic Context Types and Context Representations for Learning Word Embeddings. Proceedings of the 2017 Conference on Empirical Methods in Natural Language Processing, 2411–2421. Copenhagen, Denmark, September 7–11, 2017.
  2. Rogers, A. (2017). Multilingual Computational Lexicography: Frame Semantics Meets Distributional Semantics (Ph.D. Dissertation). University of Tokyo, Tokyo.
  3. Rogers, A., Drozd, A., & Li, B. (2017). The (Too Many) Problems of Analogical Reasoning with Word Vectors. Proceedings of the 6th Joint Conference on Lexical and Computational Semantics (* SEM 2017), 135–148.

2016

(before 2017 my last name was “Gladkova”)

  1. Drozd, A., Gladkova, A., & Matsuoka, S. (2016). Word Embeddings, Analogies, and Machine Learning: Beyond King - Man + Woman = Queen. Proceedings of COLING 2016, the 26th International Conference on Computational Linguistics: Technical Papers, 3519–3530. Osaka, Japan, December 11-17.
  2. Gladkova, A., & Drozd, A. (2016). Intrinsic Evaluations of Word Embeddings: What Can We Do Better? Proceedings of The 1st Workshop on Evaluating Vector Space Representations for NLP, 36–42. https://doi.org/10.18653/v1/W16-2507
  3. Gladkova, A., Drozd, A., & Matsuoka, S. (2016). Analogy-Based Detection of Morphological and Semantic Relations with Word Embeddings: What Works and What Doesn’t. Proceedings of the NAACL-HLT SRW, 47–54. https://doi.org/10.18653/v1/N16-2002
  4. Santus, E., Gladkova, A., Evert, S., & Lenci, A. (2016). The CogALex-V Shared Task on the Corpus-Based Identification of Semantic Relations. Proceedings of the 5th Workshop on Cognitive Aspects of the Lexicon (CogALex-V), 69–79. Osaka, Japan, December 11-17: ACL.

2015

  1. Drozd, A., Gladkova, A., & Matsuoka, S. (2015). Discovering Aspectual Classes of Russian Verbs in Untagged Large Corpora. Proceedings of 2015 IEEE International Conference on Data Science and Data Intensive Systems (DSDIS), 61–68. https://doi.org/10.1109/DSDIS.2015.30
    This paper presents a case study of discovering and classifying verbs in large web-corpora. Many tasks in natural language processing require corpora containing billions of words, and with such volumes of data co-occurrence extraction becomes one of the performance bottlenecks in the Vector Space Models of computational linguistics. We propose a co-occurrence extraction kernel based on ternary trees as an alternative (or a complimentary stage) to conventional map-reduce based approach, this kernel achieves an order of magnitude improvement in memory footprint and processing speed. Our classifier successfully and efficiently identified verbs in a 1.2-billion words untagged corpus of Russian fiction and distinguished between their two aspectual classes. The model proved efficient even for low-frequency vocabulary, including nonce verbs and neologisms.
  2. Drozd, A., Gladkova, A., & Matsuoka, S. (2015). Python, Performance, and Natural Language Processing. Proceedings of the 5th Workshop on Python for High-Performance and Scientific Computing, 1:1–1:10. https://doi.org/10.1145/2835857.2835858
    We present a case study of Python-based workflow for a data-intensive natural language processing problem, namely word classification with vector space model methodology. Problems in the area of natural language processing are typically solved in many steps which require transformation of the data to vastly different formats (in our case, raw text to sparse matrices to dense vectors). A Python implementation for each of these steps would require a different solution. We survey existing approaches to using Python for high-performance processing of large volumes of data, and we propose a sample solution for each step for our case study (aspectual classification of Russian verbs), attempting to preserve both efficiency and user-friendliness. For the most computationally intensive part of the workflow we develop a prototype distributed implementation of co-occurrence extraction module using IPython.parallel cluster.