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Balaji Lakshminarayanan

25 accepted papers

2023

A Simple Zero-shot Prompt Weighting Technique to Improve Prompt Ensembling in Text-Image Models

ICML 2023poster

Contrastively trained text-image models have the remarkable ability to perform zero-shot classification, that is, classifying previously unseen images into categories that the model has never been explicitly trained to identify. However, these zero-shot classifiers need prompt engineering to achieve…

Cited by 47SourcePDFScholar
2023

Improving Zero-Shot Generalization and Robustness of Multi-Modal Models

CVPR 2023poster

Multi-modal image-text models such as CLIP and LiT have demonstrated impressive performance on image classification benchmarks and their zero-shot generalization ability is particularly exciting. While the top-5 zero-shot accuracies of these models are very high, the top-1 accuracies are much lower…

2023

Improving the Robustness of Summarization Models by Detecting and Removing Input Noise

EMNLP 2023long findings

The evaluation of abstractive summarization models typically uses test data that is identically distributed as training data. In real-world practice, documents to be summarized may contain input noise caused by text extraction artifacts or data pipeline bugs. The robustness of model performance unde…

Cited by 0SourceScholar
2023

Out-of-Distribution Detection and Selective Generation for Conditional Language Models

ICLR 2023top-25%

Machine learning algorithms typically assume independent and identically distributed samples in training and at test time (IID). Much work has shown that high-performing ML classifiers can degrade significantly and provide overly-confident, wrong classification predictions, particularly for out-of-…

Cited by 106SourcePDFScholar
2023

Pushing the Accuracy-Group Robustness Frontier with Introspective Self-play

ICLR 2023poster

Standard empirical risk minimization (ERM) training can produce deep neural network (DNN) models that are accurate on average but under-perform in under-represented population subgroups, especially when there are imbalanced group distributions in the long-tailed training data. Therefore, approaches…

Cited by 2SourcePDFScholar
2022

Understanding and Improving Robustness of Vision Transformers through Patch-based Negative Augmentation

NeurIPS 2022accept

We investigate the robustness of vision transformers (ViTs) through the lens of their special patch-based architectural structure, i.e., they process an image as a sequence of image patches. We find that ViTs are surprisingly insensitive to patch-based transformations, even when the transformation l…

Cited by 51SourcePDFScholar
2021

Combining Ensembles and Data Augmentation Can Harm Your Calibration

ICLR 2021poster

Ensemble methods which average over multiple neural network predictions are a simple approach to improve a model’s calibration and robustness. Similarly, data augmentation techniques, which encode prior information in the form of invariant feature transformations, are effective for improving calibra…

Cited by 78SourcePDFScholar
2021

Density of States Estimation for Out of Distribution Detection

AISTATS 2021poster

Perhaps surprisingly, recent studies have shown probabilistic model likelihoods have poor specificity for out-of-distribution (OOD) detection and often assign higher likelihoods to OOD data than in-distribution data. To ameliorate this issue we propose DoSE, the density of states estimator. Drawing…

Cited by 108SourcePDFScholar
2021

Soft Calibration Objectives for Neural Networks

NeurIPS 2021poster

Optimal decision making requires that classifiers produce uncertainty estimates consistent with their empirical accuracy. However, deep neural networks are often under- or over-confident in their predictions. Consequently, methods have been developed to improve the calibration of their predictive un…

Cited by 97SourcePDFScholar
2021

Training independent subnetworks for robust prediction

ICLR 2021poster

Recent approaches to efficiently ensemble neural networks have shown that strong robustness and uncertainty performance can be achieved with a negligible gain in parameters over the original network. However, these methods still require multiple forward passes for prediction, leading to a significa…

2020

AugMix: A Simple Data Processing Method to Improve Robustness and Uncertainty

ICLR 2020poster

Modern deep neural networks can achieve high accuracy when the training distribution and test distribution are identically distributed, but this assumption is frequently violated in practice. When the train and test distributions are mismatched, accuracy can plummet. Currently there are few techniqu…

Cited by 1605SourcecodeScholar
2020

Bayesian Deep Ensembles via the Neural Tangent Kernel

NeurIPS 2020poster

We explore the link between deep ensembles and Gaussian processes (GPs) through the lens of the Neural Tangent Kernel (NTK): a recent development in understanding the training dynamics of wide neural networks (NNs). Previous work has shown that even in the infinite width limit, when NNs become GPs,…

2020

Efficient and Scalable Bayesian Neural Nets with Rank-1 Factors

ICML 2020poster

Bayesian neural networks (BNNs) demonstrate promising success in improving the robustness and uncertainty quantification of modern deep learning. However, they generally struggle with underfitting at scale and parameter efficiency. On the other hand, deep ensembles have emerged as alternatives for u…

2020

Simple and Principled Uncertainty Estimation with Deterministic Deep Learning via Distance Awareness

NeurIPS 2020poster

Bayesian neural networks (BNN) and deep ensembles are principled approaches to estimate the predictive uncertainty of a deep learning model. However their practicality in real-time, industrial-scale applications are limited due to their heavy memory and inference cost. This motivates us to study pr…

2019

Can you trust your model's uncertainty? Evaluating predictive uncertainty under dataset shift

NeurIPS 2019poster

Modern machine learning methods including deep learning have achieved great success in predictive accuracy for supervised learning tasks, but may still fall short in giving useful estimates of their predictive uncertainty. Quantifying uncertainty is especially critical in real-world settings, which…

2019

Do Deep Generative Models Know What They Don't Know?

ICLR 2019poster

A neural network deployed in the wild may be asked to make predictions for inputs that were drawn from a different distribution than that of the training data. A plethora of work has demonstrated that it is easy to find or synthesize inputs for which a neural network is highly confident yet wrong.…

Cited by 903SourcePDFScholar
2019

Hybrid Models with Deep and Invertible Features

ICML 2019oral

We propose a neural hybrid model consisting of a linear model defined on a set of features computed by a deep, invertible transformation (i.e. a normalizing flow). An attractive property of our model is that both p(features), the density of the features, and p(targets|features), the predictive distr…

Cited by 110SourcePDFScholar
2019

Learning from Delayed Outcomes via Proxies with Applications to Recommender Systems

ICML 2019oral

Predicting delayed outcomes is an important problem in recommender systems (e.g., if customers will finish reading an ebook). We formalize the problem as an adversarial, delayed online learning problem and consider how a proxy for the delayed outcome (e.g., if customers read a third of the book in 2…

Cited by 15SourcePDFScholar
2019

Likelihood Ratios for Out-of-Distribution Detection

NeurIPS 2019poster

Discriminative neural networks offer little or no performance guarantees when deployed on data not generated by the same process as the training distribution. On such out-of-distribution (OOD) inputs, the prediction may not only be erroneous, but confidently so, limiting the safe deployment of class…

2018

Many Paths to Equilibrium: GANs Do Not Need to Decrease a Divergence At Every Step

ICLR 2018poster

Generative adversarial networks (GANs) are a family of generative models that do not minimize a single training criterion. Unlike other generative models, the data distribution is learned via a game between a generator (the generative model) and a discriminator (a teacher providing training signal)…

Cited by 265SourcePDFScholar
2017

Simple and Scalable Predictive Uncertainty Estimation using Deep Ensembles

NeurIPS 2017spotlight

Deep neural networks (NNs) are powerful black box predictors that have recently achieved impressive performance on a wide spectrum of tasks. Quantifying predictive uncertainty in NNs is a challenging and yet unsolved problem. Bayesian NNs, which learn a distribution over weights, are currently the…

Cited by 7516SourcePDFScholar
2016

Mondrian Forests for Large-Scale Regression when Uncertainty Matters

AISTATS 2016poster

Many real-world regression problems demand a measure of the uncertainty associated with each prediction. Standard decision forests deliver efficient state-of-the-art predictive performance, but high-quality uncertainty estimates are lacking. Gaussian processes (GPs) deliver uncertainty estimates, b…

Cited by 67SourcePDFScholar