Portrait de Alessandro Sordoni

Alessandro Sordoni

Membre industriel principal
Professeur associé, Université de Montréal, Département d'informatique et de recherche opérationnelle
Chercheur scientifique, Microsoft Research Montréal
Sujets de recherche
Grands modèles de langage (LLM)
Raisonnement
Traitement du langage naturel

Biographie

Je suis chercheur principal à Microsoft Research Montréal. J'ai obtenu un doctorat de l'Université de Montréal sous la direction de Jian-Yun Nie, en étudiant comment représenter efficacement les documents et les requêtes pour la recherche d'information. Présentement, je m’intéresse à l'étude de l'efficacité de l'apprentissage et de la généralisation systématique dans les grands modèles actuels d'apprentissage profond. Mes intérêts s'étendent à l'apprentissage non supervisé et à l'apprentissage à petite échelle, en particulier dans le domaine du langage naturel.

Étudiants actuels

Collaborateur·rice alumni - University of Copenhagen

Publications

Towards Policy-Guided Conversational Recommendation with Dialogue Acts
Paul Crook
Y-Lan Boureau
J. Weston
Akbar Karimi
Leonardo Rossi
Andrea Prati
Wenqiang Lei
Xiangnan He
Qingyun Yisong Miao
Richang Wu
Min-Yen Hong
Kan Tat-Seng
Raymond Li
Hannes Schulz
Zujie Liang
Huang Hu
Can Xu
Jian Miao
Lizi Liao … (voir 47 de plus)
Ryuichi Takanobu
Yunshan Ma
Xun Yang
Wenchang Ma
Minlie Huang
Minghao Tu
Iulian Serban
Aaron C. Courville
David Silver
Julian Schrittwieser
K. Simonyan
Ioannis Antonoglou
Aja Huang
A. Guez
Hanlin Zhu
O. Vinyals
Igor Babuschkin
M. Mathieu
Max Jaderberg
Wojciech M. Czar-725 necki
A. Dudzik
Petko Georgiev
Richard Powell
T. Ewalds
Dan Horgan
M. Kroiss
Ivo Danihelka
J. Agapiou
Junhyuk Oh
Valentin Dalibard
David Choi
L. Sifre
Yury Sulsky
Sasha Vezhnevets
James Molloy
Trevor Cai
D. Budden
T. Paine
Ziyu Wang
Tobias Pfaff
Tobias Pohlen
Explicitly Modeling Syntax in Language Models with Incremental Parsing and a Dynamic Oracle
Syntax is fundamental to our thinking about language. Failing to capture the structure of input language could lead to generalization proble… (voir plus)ms and over-parametrization. In the present work, we propose a new syntax-aware language model: Syntactic Ordered Memory (SOM). The model explicitly models the structure with an incremental parser and maintains the conditional probability setting of a standard language model (left-to-right). To train the incremental parser and avoid exposure bias, we also propose a novel dynamic oracle, so that SOM is more robust to wrong parsing decisions. Experiments show that SOM can achieve strong results in language modeling, incremental parsing and syntactic generalization tests, while using fewer parameters than other models.
Understanding by Understanding Not: Modeling Negation in Language Models
Negation is a core construction in natural language. Despite being very successful on many tasks, state-of-the-art pre-trained language mode… (voir plus)ls often handle negation incorrectly. To improve language models in this regard, we propose to augment the language modeling objective with an unlikelihood objective that is based on negated generic sentences from a raw text corpus. By training BERT with the resulting combined objective we reduce the mean top~1 error rate to 4% on the negated LAMA dataset. We also see some improvements on the negated NLI benchmarks.
What Makes Machine Reading Comprehension Questions Difficult? Investigating Variation in Passage Sources and Question Types
Susan Bartlett
Grzegorz Kondrak
Max Bartolo
Alastair Roberts
Johannes Welbl
Steven Bird
Ewan Klein
Edward Loper
Samuel R. Bowman
George Dahl. 2021
What
Chao Pang
Junyuan Shang
Jiaxiang Liu
Xuyi Chen
Yanbin Zhao
Yuxiang Lu
Weixin Liu
Zhi-901 hua Wu
Weibao Gong … (voir 21 de plus)
Jianzhong Liang
Zhizhou Shang
Peng Sun
Ouyang Xuan
Dianhai
Houwen Tian
Hua Wu
Haifeng Wang
Adam Trischler
Tong Wang
Xingdi Yuan
Justin Har-908
Philip Bachman
Adina Williams
Nikita Nangia
Zhilin Yang
Peng Qi
ing. In
For a natural language understanding bench-001 mark to be useful in research, it has to con-002 sist of examples that are diverse and diffi… (voir plus)-003 cult enough to discriminate among current and 004 near-future state-of-the-art systems. However, 005 we do not yet know how best to select pas-006 sages to collect a variety of challenging exam-007 ples. In this study, we crowdsource multiple-008 choice reading comprehension questions for 009 passages taken from seven qualitatively dis-010 tinct sources, analyzing what attributes of pas-011 sages contribute to the difficulty and question 012 types of the collected examples. To our sur-013 prise, we find that passage source, length, and 014 readability measures do not significantly affect 015 question difficulty. Through our manual anno-016 tation of seven reasoning types, we observe 017 several trends between passage sources and 018 reasoning types, e.g., logical reasoning is more 019 often required in questions written for techni-020 cal passages. These results suggest that when 021 creating a new benchmark dataset, selecting a 022 diverse set of passages can help ensure a di-023 verse range of question types, but that passage 024 difficulty need not be a priority. 025
Recursive Top-Down Production for Sentence Generation with Latent Trees
We model the recursive production property of context-free grammars for natural and synthetic languages. To this end, we present a dynamic p… (voir plus)rogramming algorithm that marginalises over latent binary tree structures with
Explicitly Modeling Syntax in Language Model improves Generalization
Syntax is fundamental to our thinking about language. Although neural networks are very successful in many tasks, they do not explicitly mod… (voir plus)el syntactic structure. Failing to capture the structure of inputs could lead to generalization problems and over-parametrization. In the present work, we propose a new syntax-aware language model: Syntactic Ordered Memory (SOM). The model explicitly models the structure with a one-step look-ahead parser and maintains the conditional probability setting of the standard language model. Experiments show that SOM can achieve strong results in language modeling and syntactic generalization tests, while using fewer parameters then other models.
Ordered Memory
Stack-augmented recurrent neural networks (RNNs) have been of interest to the deep learning community for some time. However, the difficulty… (voir plus) of training memory models remains a problem obstructing the widespread use of such models. In this paper, we propose the Ordered Memory architecture. Inspired by Ordered Neurons (Shen et al., 2018), we introduce a new attention-based mechanism and use its cumulative probability to control the writing and erasing operation of the memory. We also introduce a new Gated Recursive Cell to compose lower-level representations into higher-level representation. We demonstrate that our model achieves strong performance on the logical inference task (Bowman et al., 2015)and the ListOps (Nangia and Bowman, 2018) task. We can also interpret the model to retrieve the induced tree structure, and find that these induced structures align with the ground truth. Finally, we evaluate our model on the Stanford SentimentTreebank tasks (Socher et al., 2013), and find that it performs comparatively with the state-of-the-art methods in the literature.
Brief Report: Ordered Neurons: Integrating Tree Structures into Recurrent Neural Networks
An Empirical Study of Example Forgetting During Deep Neural Network Learning
Mariya Toneva
Remi Tachet des Combes
Adam Trischler
Geoffrey J. Gordon
Inspired by the phenomenon of catastrophic forgetting, we investigate the learning dynamics of neural networks as they train on single class… (voir plus)ification tasks. Our goal is to understand whether a related phenomenon occurs when data does not undergo a clear distributional shift. We define a `forgetting event' to have occurred when an individual training example transitions from being classified correctly to incorrectly over the course of learning. Across several benchmark data sets, we find that: (i) certain examples are forgotten with high frequency, and some not at all; (ii) a data set's (un)forgettable examples generalize across neural architectures; and (iii) based on forgetting dynamics, a significant fraction of examples can be omitted from the training data set while still maintaining state-of-the-art generalization performance.
Ordered Neurons: Integrating Tree Structures into Recurrent Neural Networks
Natural language is hierarchically structured: smaller units (e.g., phrases) are nested within larger units (e.g., clauses). When a larger c… (voir plus)onstituent ends, all of the smaller constituents that are nested within it must also be closed. While the standard LSTM architecture allows different neurons to track information at different time scales, it does not have an explicit bias towards modeling a hierarchy of constituents. This paper proposes to add such an inductive bias by ordering the neurons; a vector of master input and forget gates ensures that when a given neuron is updated, all the neurons that follow it in the ordering are also updated. Our novel recurrent architecture, ordered neurons LSTM (ON-LSTM), achieves good performance on four different tasks: language modeling, unsupervised parsing, targeted syntactic evaluation, and logical inference.
Augmented CycleGAN: Learning Many-to-Many Mappings from Unpaired Data
Amjad Almahairi
Sai Rajeswar
Philip Bachman
Learning inter-domain mappings from unpaired data can improve performance in structured prediction tasks, such as image segmentation, by red… (voir plus)ucing the need for paired data. CycleGAN was recently proposed for this problem, but critically assumes the underlying inter-domain mapping is approximately deterministic and one-to-one. This assumption renders the model ineffective for tasks requiring flexible, many-to-many mappings. We propose a new model, called Augmented CycleGAN, which learns many-to-many mappings between domains. We examine Augmented CycleGAN qualitatively and quantitatively on several image datasets.
Focused Hierarchical RNNs for Conditional Sequence Processing
Recurrent Neural Networks (RNNs) with attention mechanisms have obtained state-of-the-art results for many sequence processing tasks. Most o… (voir plus)f these models use a simple form of encoder with attention that looks over the entire sequence and assigns a weight to each token independently. We present a mechanism for focusing RNN encoders for sequence modelling tasks which allows them to attend to key parts of the input as needed. We formulate this using a multi-layer conditional sequence encoder that reads in one token at a time and makes a discrete decision on whether the token is relevant to the context or question being asked. The discrete gating mechanism takes in the context embedding and the current hidden state as inputs and controls information flow into the layer above. We train it using policy gradient methods. We evaluate this method on several types of tasks with different attributes. First, we evaluate the method on synthetic tasks which allow us to evaluate the model for its generalization ability and probe the behavior of the gates in more controlled settings. We then evaluate this approach on large scale Question Answering tasks including the challenging MS MARCO and SearchQA tasks. Our models shows consistent improvements for both tasks over prior work and our baselines. It has also shown to generalize significantly better on synthetic tasks as compared to the baselines.