J 2025

Prediction intervals and bands with improved coverage for functional data under noisy discrete observation

KRAUS, David

Basic information

Original name

Prediction intervals and bands with improved coverage for functional data under noisy discrete observation

Authors

KRAUS, David (203 Czech Republic, guarantor, belonging to the institution)

Edition

Journal of Applied Statistics, Taylor and Francis Ltd. 2025, 0266-4763

Other information

Language

English

Type of outcome

Article in a journal

Field of Study

10103 Statistics and probability

Country of publisher

United Kingdom of Great Britain and Northern Ireland

Confidentiality degree

is not subject to a state or trade secret

References:

Impact factor

Impact factor: 1.200 in 2023

Organization unit

Faculty of Science

UT WoS

001343886300001

EID Scopus

2-s2.0-85207935495

Keywords in English

Coverage; curve reconstruction; functional data analysis; noisy discrete observation; prediction set; spline smoothing

Tags

Tags

International impact, Reviewed
Changed: 20/5/2025 12:58, Mgr. Marie Novosadová Šípková, DiS.

Abstract

V originále

We revisit the classic situation in functional data analysis in which curves are observed at discrete, possibly sparse and irregular, arguments with observation noise. We focus on the reconstruction of individual curves by prediction intervals and bands. The standard approach consists of two steps: first, one estimates the mean and covariance function of curves and observation noise variance function by, e.g. penalized splines, and second, under Gaussian assumptions, one derives the conditional distribution of a curve given observed data and constructs prediction sets with required properties, usually employing sampling from the predictive distribution. This approach is well established, commonly used and theoretically valid but practically, it surprisingly fails in its key property: prediction sets constructed this way often do not have the required coverage. The actual coverage is lower than the nominal one. We investigate the cause of this issue and propose a computationally feasible remedy that leads to prediction regions with a much better coverage. Our method accounts for the uncertainty of the predictive model by sampling from the approximate distribution of its spline estimators whose covariance is estimated by a novel sandwich estimator. Our approach also applies to the important case of covariate-adjusted models.