Information-Theoretic Probing with Minimum Description Length
Written for the Research library (claude-opus-5-5) from the paper text. Original — aclanthology.org/2020.emnlp-main.14.pdf
Summary
Probing classifiers measure how well frozen representations, such as those from ELMo or BERT, encode a linguistic property. Their accuracy is a poor guide, though. It barely separates pretrained from randomly initialized representations, and it can look similar for real labels and for random control tasks. Earlier work got around this by hand-limiting probe size or training data. Voita and Titov reframe probing in information-theoretic terms: the probe's job is to transmit the labels efficiently given the representations. The metric becomes the minimum description length (MDL) of the labels, not accuracy. This length combines how well the data fit with the effort needed to reach that fit, meaning model complexity or the amount of data required. Two estimators fit easily into standard probing pipelines: variational coding, which explicitly charges for the probe's weights, and online coding, which transmits data block by block and relates to the area under the learning curve. The two estimators agree with each other. They also separate representations more clearly and more stably than accuracy, and no manual tuning of probe settings is needed.
Key points
- Two estimators of MDL are compared. Variational code is a two-part code whose cost equals a variational learning loss. Online code accounts for the model only indirectly, by training on growing data prefixes. Both are measured against a uniform-code baseline of n·log₂K bits.
- Achievable compression is bounded by the mutual information between representations and labels. The model-cost term captures how easy the labels are to extract, which corresponds to the "ease of extraction" idea discussed by Pimentel et al. (2020).
- On control tasks (Hewitt and Liang, 2019), accuracies can be close, but MDL shows the difference. The linguistic task is solved with a small probe, while the random task needs a large one, and these sizes come out of MDL optimization rather than manual search.
- On tasks such as Rel. (SemEval), Entities and SRL, codelengths for contextual layers are roughly half those of the embedding layer (LAYER 0). Randomly initialized models compress worse than trained ones. Their layers also give identical MDL, while for the trained model LAYER 2 is worse than LAYER 1.
- Code is released at github.com/lena-voita/description-length-probing.
Cited by
- Probing Classifiers: Promises, Shortcomings, and Advances
- True Few-Shot Learning with Language Models
- Information-Theoretic Probing for Linguistic Structure
- AutoPrompt: Eliciting Knowledge from Language Models with Automatically Generated Prompts
- Masked Language Modeling and the Distributional Hypothesis: Order Word Matters Pre-training for Little
- Probing Pretrained Language Models for Lexical Semantics
- Factual Probing Is [MASK]: Learning vs. Learning to Recall
Cite
@inproceedings{voita2020information,
title = {{Information-Theoretic Probing with Minimum Description Length}},
author = {Voita, Elena and Titov, Ivan},
booktitle = {Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)},
year = {2020},
doi = {10.18653/v1/2020.emnlp-main.14},
url = {https://doi.org/10.18653/v1/2020.emnlp-main.14}
}References
- Anthony Bau, Yonatan Belinkov, Hassan Sajjad, Nadir Durrani, Fahim Dalvi, and James Glass. 2019. Identifying and controlling important neurons in neural machine translation. In International Conference on Learning Representations, New Orleans. find
- Yonatan Belinkov and James Glass. 2019. Analysis methods in neural language processing: A survey. find our card
- Zhengbao Jiang, Frank F Xu, Jun Araki, and Graham Neubig. 2019. How can we know what language models know? arXiv preprint arXiv:1911.12543. find our card
- Transactions of the Association for Computational Linguistics, 7:49–72. find
- Léonard Blier and Yann Ollivier. 2018. The description length of deep learning models. In Advances in Neural Information Processing Systems, pages 2216–2226. find
- Ciprian Chelba, Tomas Mikolov, Mike Schuster, Qi Ge, Thorsten Brants, Phillipp Koehn, and Tony Robinson. 2014. One billion word benchmark for measuring progress in statistical language modeling. In Fifteenth Annual Conference of the International Speech Communication Association. find our card
- Kevin Clark, Urvashi Khandelwal, Omer Levy, and Christopher D. Manning. 2019. What does BERT look at? an analysis of BERT’s attention. In Proceedings of the 2019 ACL Workshop BlackboxNLP: Analyzing and Interpreting Neural Networks for NLP, pages 276–286, Florence, Italy. Association for Computationa… find
- Jacob Devlin, Ming-Wei Chang, Kenton Lee, and Kristina Toutanova. 2019. BERT: Pre-training of deep bidirectional transformers for language understanding. In Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies,… find
- Andrej Karpathy, Justin Johnson, and Li Fei-Fei. 2015. Visualizing and understanding recurrent networks. arXiv preprint arXiv:1506.02078. find our card
- Diederik Kingma and Jimmy Ba. 2015. Adam: A method for stochastic optimization. In Proceedings of the International Conference on Learning Representation (ICLR 2015). find
- Olga Kovaleva, Alexey Romanov, Anna Rogers, and Anna Rumshisky. 2019. Revealing the dark secrets of BERT. In Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP), pages 4365–437… find our card
- Kenton Lee, Luheng He, Mike Lewis, and Luke Zettlemoyer. 2017. End-to-end neural coreference resolution. In Proceedings of the 2017 Conference on Empirical Methods in Natural Language Processing, pages 188–197, Copenhagen, Denmark. Association for Computational Linguistics. find our card
- Tal Linzen, Emmanuel Dupoux, and Yoav Goldberg. 2016. Assessing the ability of lstms to learn syntax-sensitive dependencies. Transactions of the Association for Computational Linguistics, 4:521–535. find our card
- Christos Louizos, Karen Ullrich, and Max Welling. 2017. Bayesian compression for deep learning. In Advances in Neural Information Processing Systems, pages 3288–3298. find
- Peter Grunwald. 2004. A tutorial introduction to the minimum description length principle. arXiv preprint math/0406077. find
- Kristina Gulordava, Piotr Bojanowski, Edouard Grave, Tal Linzen, and Marco Baroni. 2018. Colorless green recurrent networks dream hierarchically. In Proceedings of the 2018 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume… find our card
- John Hewitt and Percy Liang. 2019. Designing and interpreting probes with control tasks. In Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP), pages 2733–2743, Hong Kong, Chi… find
- GE Hinton and D von Cramp. 1993. Keeping neural networks simple by minimising the description length of weights. In Proceedings of COLT-93, pages 5–13. find
- Antti Honkela and Harri Valpola. 2004. Variational learning and bits-back coding: an information-theoretic view to bayesian learning. In IEEE Transactions on Neural Networks, volume 15, pages 800– 810. find
- David JC MacKay. 2003. Information theory, inference and learning algorithms. Cambridge university press. find
- Mitchell P. Marcus, Beatrice Santorini, and Mary Ann Marcinkiewicz. 1993. Building a large annotated corpus of English: The Penn Treebank. Computational Linguistics, 19(2):313–330. find our card
- Rebecca Marvin and Tal Linzen. 2018. Targeted syntactic evaluation of language models. In Proceedings of the 2018 Conference on Empirical Methods in Natural Language Processing, pages 1192–1202, Brussels, Belgium. Association for Computational Linguistics. find
- Dmitry Molchanov, Arsenii Ashukha, and Dmitry Vetrov. 2017. Variational dropout sparsifies deep neural networks. In Proceedings of the 34th International Conference on Machine Learning. find
- Matthew Peters, Mark Neumann, Mohit Iyyer, Matt Gardner, Christopher Clark, Kenton Lee, and Luke Zettlemoyer. 2018. Deep contextualized word representations. In Proceedings of the 2018 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technolog… find
- Fabio Petroni, Tim Rocktäschel, Sebastian Riedel, Patrick Lewis, Anton Bakhtin, Yuxiang Wu, and Alexander Miller. 2019. Language models as knowledge bases? In Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural… find our card
- Alon Talmor, Yanai Elazar, Yoav Goldberg, and Jonathan Berant. 2019. olmpics – on what language model pre-training captures. arXiv preprint arXiv:1912.13283. find our card
- Ian Tenney, Patrick Xia, Berlin Chen, Alex Wang, Adam Poliak, R Thomas McCoy, Najoung Kim, Benjamin Van Durme, Samuel R Bowman, Dipanjan Das, et al. 2019. What do you learn from context? probing for sentence structure in contextualized word representations. In International Conference on Learning Re… find our card
- Ngoc-Quan Pham, German Kruszewski, and Gemma Boleda. 2016. Convolutional neural network language models. In Proceedings of the 2016 Conference on Empirical Methods in Natural Language Processing, pages 1153–1162, Austin, Texas. Association for Computational Linguistics. find
- Ke Tran, Arianna Bisazza, and Christof Monz. 2018. The importance of being recurrent for modeling hierarchical structure. In Proceedings of the 2018 Conference on Empirical Methods in Natural Language Processing, pages 4731–4736, Brussels, Belgium. Association for Computational Linguistics. find
- Tiago Pimentel, Josef Valvoda, Rowan Hall Maudslay, Ran Zmigrod, Adina Williams, and Ryan Cotterell. 2020. Information-theoretic probing for linguistic structure. In Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics, pages 4609–4622, Online. Association for Comp… find our card
- Elena Voita, Rico Sennrich, and Ivan Titov. 2019a. The bottom-up evolution of representations in the transformer: A study with machine translation and language modeling objectives. In Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joi… find
- Nina Poerner, Ulli Waltinger, and Hinrich Schütze. 2019. Bert is not a knowledge base (yet): Factual knowledge vs. name-based reasoning in unsupervised qa. arXiv preprint arXiv:1911.03681. find
- Peng Qi and Christopher D. Manning. 2017. Arc-swift: A novel transition system for dependency parsing. In Proceedings of the 55th Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers), pages 110–117, Vancouver, Canada. Association for Computational Linguistics. find our card
- Alec Radford, Jeffrey Wu, Rewon Child, David Luan, Dario Amodei, and Ilya Sutskever. 2019. Language models are unsupervised multitask learners. OpenAI Blog, 1(8):9. find
- Alessandro Raganato and Jörg Tiedemann. 2018. An analysis of encoder representations in transformer-based machine translation. In Proceedings of the 2018 EMNLP Workshop BlackboxNLP: Analyzing and Interpreting Neural Networks for NLP, pages 287–297, Brussels, Belgium. Association for Computational Li… find
- Jorma Rissanen. 1984. Universal coding, information, prediction, and estimation. IEEE Transactions on Information theory, 30(4):629–636. find
- Naomi Saphra and Adam Lopez. 2019. Understanding learning dynamics of language models with SVCCA. In 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), pages 3257–3267, Minn… find
- Elena Voita, Pavel Serdyukov, Rico Sennrich, and Ivan Titov. 2018. Context-aware neural machine translation learns anaphora resolution. In Proceedings of the 56th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 1264–1274, Melbourne, Australia. Associati… find our card
- Elena Voita, David Talbot, Fedor Moiseev, Rico Sennrich, and Ivan Titov. 2019b. Analyzing multi-head self-attention: Specialized heads do the heavy lifting, the rest can be pruned. In Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics, pages 5797–5808, Florence,… find our card
- John Wieting and Douwe Kiela. 2019. No training required: Exploring random encoders for sentence classification. In International Conference on Learning Representations. find
- Dani Yogatama, Cyprien de Masson d’Autume, Jerome Connor, Tomas Kocisky, Mike Chrzanowski, Lingpeng Kong, Angeliki Lazaridou, Wang Ling, Lei Yu, Chris Dyer, and Phil Blunsom. 2019. Learning and evaluating general linguistic intelligence. arXiv preprint arXiv:1901.11373. find
- Kelly Zhang and Samuel Bowman. 2018. Language modeling teaches you more than translation does: Lessons learned through auxiliary syntactic task analysis. In Proceedings of the 2018 EMNLP Workshop BlackboxNLP: Analyzing and Interpreting Neural Networks for NLP, pages 359–361, Brussels, Belgium. Assoc… find