Diffusion Transformers for Imputation: Statistical Efficiency and Uncertainty Quantification

Fuente: arXiv
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Main Authors: Ye, Zeqi, Chen, Minshuo
Format: Preprint
Published: 2025
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author Ye, Zeqi
Chen, Minshuo
author_facet Ye, Zeqi
Chen, Minshuo
contents Imputation methods play a critical role in enhancing the quality of practical time-series data, which often suffer from pervasive missing values. Recently, diffusion-based generative imputation methods have demonstrated remarkable success compared to autoregressive and conventional statistical approaches. Despite their empirical success, the theoretical understanding of how well diffusion-based models capture complex spatial and temporal dependencies between the missing values and observed ones remains limited. Our work addresses this gap by investigating the statistical efficiency of conditional diffusion transformers for imputation and quantifying the uncertainty in missing values. Specifically, we derive statistical sample complexity bounds based on a novel approximation theory for conditional score functions using transformers, and, through this, construct tight confidence regions for missing values. Our findings also reveal that the efficiency and accuracy of imputation are significantly influenced by the missing patterns. Furthermore, we validate these theoretical insights through simulation and propose a mixed-masking training strategy to enhance the imputation performance.
format Preprint
id arxiv_https___arxiv_org_abs_2510_02216
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Diffusion Transformers for Imputation: Statistical Efficiency and Uncertainty Quantification
Ye, Zeqi
Chen, Minshuo
Machine Learning
Statistics Theory
Imputation methods play a critical role in enhancing the quality of practical time-series data, which often suffer from pervasive missing values. Recently, diffusion-based generative imputation methods have demonstrated remarkable success compared to autoregressive and conventional statistical approaches. Despite their empirical success, the theoretical understanding of how well diffusion-based models capture complex spatial and temporal dependencies between the missing values and observed ones remains limited. Our work addresses this gap by investigating the statistical efficiency of conditional diffusion transformers for imputation and quantifying the uncertainty in missing values. Specifically, we derive statistical sample complexity bounds based on a novel approximation theory for conditional score functions using transformers, and, through this, construct tight confidence regions for missing values. Our findings also reveal that the efficiency and accuracy of imputation are significantly influenced by the missing patterns. Furthermore, we validate these theoretical insights through simulation and propose a mixed-masking training strategy to enhance the imputation performance.
title Diffusion Transformers for Imputation: Statistical Efficiency and Uncertainty Quantification
topic Machine Learning
Statistics Theory
url https://arxiv.org/abs/2510.02216