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Pavel Izmailov

20 accepted papers

2024

Weak-to-Strong Generalization: Eliciting Strong Capabilities With Weak Supervision

ICML 2024oral

Widely used alignment techniques, such as reinforcement learning from human feedback (RLHF), rely on the ability of humans to supervise model behavior---for example, to evaluate whether a model faithfully followed instructions or generated safe outputs. However, future superhuman models will behave…

Cited by 260SourcePDFScholar
2023

FlexiViT: One Model for All Patch Sizes

CVPR 2023poster

Vision Transformers convert images to sequences by slicing them into patches. The size of these patches controls a speed/accuracy tradeoff, with smaller patches leading to higher accuracy at greater computational cost, but changing the patch size typically requires retraining the model. In this pape…

2023

Last Layer Re-Training is Sufficient for Robustness to Spurious Correlations

ICLR 2023top-25%

Neural network classifiers can largely rely on simple spurious features, such as image backgrounds, to make predictions. However, even in these cases, we show that they still often learn core features associated with the desired attributes of the data, contrary to recent findings. Inspired by this i…

2023

Simple and Fast Group Robustness by Automatic Feature Reweighting

ICML 2023poster

A major challenge to out-of-distribution generalization is reliance on spurious features --- patterns that are predictive of the class label in the training data distribution, but not causally related to the target. Standard methods for reducing the reliance on spurious features typically assume tha…

2022

Bayesian Model Selection, the Marginal Likelihood, and Generalization

ICML 2022oral

How do we compare between hypotheses that are entirely consistent with observations? The marginal likelihood (aka Bayesian evidence), which represents the probability of generating our observations from a prior, provides a distinctive approach to this foundational question, automatically encoding Oc…

2022

On Feature Learning in the Presence of Spurious Correlations

NeurIPS 2022accept

Deep classifiers are known to rely on spurious features — patterns which are correlated with the target on the training data but not inherently relevant to the learning problem, such as the image backgrounds when classifying the foregrounds. In this paper we evaluate the amount of information about…

2022

On Uncertainty, Tempering, and Data Augmentation in Bayesian Classification

NeurIPS 2022accept

Aleatoric uncertainty captures the inherent randomness of the data, such as measurement noise. In Bayesian regression, we often use a Gaussian observation model, where we control the level of aleatoric uncertainty with a noise variance parameter. By contrast, for Bayesian classification we use a cat…

2021

Dangers of Bayesian Model Averaging under Covariate Shift

NeurIPS 2021poster

Approximate Bayesian inference for neural networks is considered a robust alternative to standard training, often providing good performance on out-of-distribution data. However, Bayesian neural networks (BNNs) with high-fidelity approximate inference via full-batch Hamiltonian Monte Carlo achieve p…

2021

Does Knowledge Distillation Really Work?

NeurIPS 2021poster

Knowledge distillation is a popular technique for training a small student network to emulate a larger teacher model, such as an ensemble of networks. We show that while knowledge distillation can improve student generalization, it does not typically work as it is commonly understood: there often re…

2021

What Are Bayesian Neural Network Posteriors Really Like?

ICML 2021oral

The posterior over Bayesian neural network (BNN) parameters is extremely high-dimensional and non-convex. For computational reasons, researchers approximate this posterior using inexpensive mini-batch methods such as mean-field variational inference or stochastic-gradient Markov chain Monte Carlo (S…

2020

Bayesian Deep Learning and a Probabilistic Perspective of Generalization

NeurIPS 2020poster

The key distinguishing property of a Bayesian approach is marginalization, rather than using a single setting of weights. Bayesian marginalization can particularly improve the accuracy and calibration of modern deep neural networks, which are typically underspecified by the data, and can represent m…

2020

Generalizing Convolutional Neural Networks for Equivariance to Lie Groups on Arbitrary Continuous Data

ICML 2020poster

The translation equivariance of convolutional layers enables CNNs to generalize well on image problems. While translation equivariance provides a powerful inductive bias for images, we often additionally desire equivariance to other transformations, such as rotations, especially for non-image data.…

2020

Learning Invariances in Neural Networks from Training Data

NeurIPS 2020poster

Invariances to translations have imbued convolutional neural networks with powerful generalization properties. However, we often do not know a priori what invariances are present in the data, or to what extent a model should be invariant to a given augmentation. We show how to learn invariances by p…

2020

Semi-Supervised Learning with Normalizing Flows

ICML 2020poster

Normalizing flows transform a latent distribution through an invertible neural network for a flexible and pleasingly simple approach to generative modelling, while preserving an exact likelihood. We propose FlowGMM, an end-to-end approach to generative semi supervised learning with normalizing flows…

2020

Why Normalizing Flows Fail to Detect Out-of-Distribution Data

NeurIPS 2020poster

Detecting out-of-distribution (OOD) data is crucial for robust machine learning systems. Normalizing flows are flexible deep generative models that often surprisingly fail to distinguish between in- and out-of-distribution data: a flow trained on pictures of clothing assigns higher likelihood to han…

2019

A Simple Baseline for Bayesian Uncertainty in Deep Learning

NeurIPS 2019poster

We propose SWA-Gaussian (SWAG), a simple, scalable, and general purpose approach for uncertainty representation and calibration in deep learning. Stochastic Weight Averaging (SWA), which computes the first moment of stochastic gradient descent (SGD) iterates with a modified learning rate schedule,…

2019

Subspace Inference for Bayesian Deep Learning

UAI 2019poster

Bayesian inference was once a gold standard for learning with neural networks, providing accurate full predictive distributions and well calibrated uncertainty. However, scaling Bayesian inference techniques to deep neural networks is challenging due to the high dimensionality of the parameter space…

2019

There Are Many Consistent Explanations of Unlabeled Data: Why You Should Average

ICLR 2019poster

Presently the most successful approaches to semi-supervised learning are based on consistency regularization, whereby a model is trained to be robust to small perturbations of its inputs and parameters. To understand consistency regularization, we conceptually explore how loss geometry interacts wit…

2018

Loss Surfaces, Mode Connectivity, and Fast Ensembling of DNNs

NeurIPS 2018spotlight

The loss functions of deep neural networks are complex and their geometric properties are not well understood. We show that the optima of these complex loss functions are in fact connected by simple curves, over which training and test accuracy are nearly constant. We introduce a training procedur…

2018

Scalable Gaussian Processes with Billions of Inducing Inputs via Tensor Train Decomposition

AISTATS 2018poster

We propose a method (TT-GP) for approximate inference in Gaussian Process (GP) models. We build on previous scalable GP research including stochastic variational inference based on inducing inputs, kernel interpolation, and structure exploiting algebra. The key idea of our method is to use Tensor Tr…