Label-Imbalanced and Group-Sensitive Classification under
Overparameterization
- URL: http://arxiv.org/abs/2103.01550v1
- Date: Tue, 2 Mar 2021 08:09:43 GMT
- Title: Label-Imbalanced and Group-Sensitive Classification under
Overparameterization
- Authors: Ganesh Ramachandra Kini, Orestis Paraskevas, Samet Oymak and Christos
Thrampoulidis
- Abstract summary: Label-imbalanced and group-sensitive classification seeks to appropriately modify standard training algorithms to optimize relevant metrics.
We show that a logit-adjusted loss modification to standard empirical risk minimization might be ineffective in general.
We show that our results extend naturally to binary classification with sensitive groups, thus treating the two common types of imbalances (label/group) in a unifying way.
- Score: 32.923780772605596
- License: http://creativecommons.org/publicdomain/zero/1.0/
- Abstract: Label-imbalanced and group-sensitive classification seeks to appropriately
modify standard training algorithms to optimize relevant metrics such as
balanced error and/or equal opportunity. For label imbalances, recent works
have proposed a logit-adjusted loss modification to standard empirical risk
minimization. We show that this might be ineffective in general and, in
particular so, in the overparameterized regime where training continues in the
zero training-error regime. Specifically for binary linear classification of a
separable dataset, we show that the modified loss converges to the max-margin
SVM classifier despite the logit adjustment. Instead, we propose a more general
vector-scaling loss that directly relates to the cost-sensitive SVM (CS-SVM),
thus favoring larger margin to the minority class. Through an insightful sharp
asymptotic analysis for a Gaussian-mixtures data model, we demonstrate the
efficacy of CS-SVM in balancing the errors of the minority/majority classes.
Our analysis also leads to a simple strategy for optimally tuning the involved
margin-ratio parameter. Then, we show how our results extend naturally to
binary classification with sensitive groups, thus treating the two common types
of imbalances (label/group) in a unifying way. We corroborate our theoretical
findings with numerical experiments on both synthetic and real-world datasets.
Related papers
- Covariance-corrected Whitening Alleviates Network Degeneration on Imbalanced Classification [6.197116272789107]
Class imbalance is a critical issue in image classification that significantly affects the performance of deep recognition models.
We propose a novel framework called Whitening-Net to mitigate the degenerate solutions.
In scenarios with extreme class imbalance, the batch covariance statistic exhibits significant fluctuations, impeding the convergence of the whitening operation.
arXiv Detail & Related papers (2024-08-30T10:49:33Z) - Rethinking Classifier Re-Training in Long-Tailed Recognition: A Simple
Logits Retargeting Approach [102.0769560460338]
We develop a simple logits approach (LORT) without the requirement of prior knowledge of the number of samples per class.
Our method achieves state-of-the-art performance on various imbalanced datasets, including CIFAR100-LT, ImageNet-LT, and iNaturalist 2018.
arXiv Detail & Related papers (2024-03-01T03:27:08Z) - An extended asymmetric sigmoid with Perceptron (SIGTRON) for imbalanced linear classification [0.0]
This article presents a new parameterized sigmoid called SIGTRON, and its companion convex model called SIGTRON-imbalanced classification (SIC) model.
In contrast to the conventional $pi$-weighted cost-sensitive learning model, the SIC model does not have an external $pi$-weight on the loss function.
We show that the proposed SIC model is more adaptive to variations of the dataset.
arXiv Detail & Related papers (2023-12-26T13:14:17Z) - Regularized Linear Regression for Binary Classification [20.710343135282116]
Regularized linear regression is a promising approach for binary classification problems in which the training set has noisy labels.
We show that for large enough regularization strength, the optimal weights concentrate around two values of opposite sign.
We observe that in many cases the corresponding "compression" of each weight to a single bit leads to very little loss in performance.
arXiv Detail & Related papers (2023-11-03T23:18:21Z) - A Unified Generalization Analysis of Re-Weighting and Logit-Adjustment
for Imbalanced Learning [129.63326990812234]
We propose a technique named data-dependent contraction to capture how modified losses handle different classes.
On top of this technique, a fine-grained generalization bound is established for imbalanced learning, which helps reveal the mystery of re-weighting and logit-adjustment.
arXiv Detail & Related papers (2023-10-07T09:15:08Z) - Bias Amplification Enhances Minority Group Performance [10.380812738348899]
We propose BAM, a novel two-stage training algorithm.
In the first stage, the model is trained using a bias amplification scheme via introducing a learnable auxiliary variable for each training sample.
In the second stage, we upweight the samples that the bias-amplified model misclassifies, and then continue training the same model on the reweighted dataset.
arXiv Detail & Related papers (2023-09-13T04:40:08Z) - Boosting Differentiable Causal Discovery via Adaptive Sample Reweighting [62.23057729112182]
Differentiable score-based causal discovery methods learn a directed acyclic graph from observational data.
We propose a model-agnostic framework to boost causal discovery performance by dynamically learning the adaptive weights for the Reweighted Score function, ReScore.
arXiv Detail & Related papers (2023-03-06T14:49:59Z) - Correct-N-Contrast: A Contrastive Approach for Improving Robustness to
Spurious Correlations [59.24031936150582]
Spurious correlations pose a major challenge for robust machine learning.
Models trained with empirical risk minimization (ERM) may learn to rely on correlations between class labels and spurious attributes.
We propose Correct-N-Contrast (CNC), a contrastive approach to directly learn representations robust to spurious correlations.
arXiv Detail & Related papers (2022-03-03T05:03:28Z) - Robust Neural Network Classification via Double Regularization [2.41710192205034]
We propose a novel double regularization of the neural network training loss that combines a penalty on the complexity of the classification model and an optimal reweighting of training observations.
We demonstrate DRFit, for neural net classification of (i) MNIST and (ii) CIFAR-10, in both cases with simulated mislabeling.
arXiv Detail & Related papers (2021-12-15T13:19:20Z) - PLM: Partial Label Masking for Imbalanced Multi-label Classification [59.68444804243782]
Neural networks trained on real-world datasets with long-tailed label distributions are biased towards frequent classes and perform poorly on infrequent classes.
We propose a method, Partial Label Masking (PLM), which utilizes this ratio during training.
Our method achieves strong performance when compared to existing methods on both multi-label (MultiMNIST and MSCOCO) and single-label (imbalanced CIFAR-10 and CIFAR-100) image classification datasets.
arXiv Detail & Related papers (2021-05-22T18:07:56Z) - Estimating Average Treatment Effects with Support Vector Machines [77.34726150561087]
Support vector machine (SVM) is one of the most popular classification algorithms in the machine learning literature.
We adapt SVM as a kernel-based weighting procedure that minimizes the maximum mean discrepancy between the treatment and control groups.
We characterize the bias of causal effect estimation arising from this trade-off, connecting the proposed SVM procedure to the existing kernel balancing methods.
arXiv Detail & Related papers (2021-02-23T20:22:56Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.