Organizations: Optimization and Uncertainty Quantification Department, Sandia National Laboratories, Albuquerque, NM · School of Physical and Chemical Sciences, Queen Mary University of London, London, UK and Space Weather Technology, Research and Education Center, University of Colorado, Boulder, CO · Space Weather Technology, Research and Education Center, University of Colorado, Boulder, CO · Mauna Loa Solar Observatory, National Center for Atmospheric Research, Boulder, CO · Department of Computer Science, University of Colorado Boulder, Boulder, CO
Computational models support high-stakes decisions across engineering and science, and practitioners increasingly seek probabilistic predictions to quantify uncertainty in such models. Existing approaches generate predictions either by sampling input parameter distributions or by augmenting deterministic outputs with uncertainty representations, including distribution-free and distributional methods. However, sampling-based methods are often computationally prohibitive for real-time applications, and many existing uncertainty representations either ignore input dependence or rely on restrictive Gaussian assumptions that fail to capture asymmetry and heavy-tailed behavior. Therefore, we extend the ACCurate and Reliable Uncertainty Estimate (ACCRUE) framework to learn input-dependent, non-Gaussian uncertainty distributions, specifically two-piece Gaussian and asymmetric Laplace forms, using a neural network trained with a loss function that balances predictive accuracy and reliability. Through synthetic and real-world experiments, we show that the proposed approach captures an input-dependent uncertainty structure and improves probabilistic forecasts relative to existing methods, while maintaining flexibility to model skewed and non-Gaussian errors.
Figures & tables
Scenario
A
B
C
D
E
F
Distribution
TPG
TPG
TPG
AL
AL
AL
Parameter Functions
Linear
Trig
Combo
Linear
Trig
Combo
Table 1: Synthetic data calibration scenarios
Figure 1: Numerical results for scenario A: TPG with linear parameters
Figure 2: Numerical results for scenario B: TPG with trig parameters
Figure 3: Numerical results for scenario C: TPG with combo parameters
Figure 4: Numerical results for scenario D: AL with linear parameters
Figure 5: Numerical results for scenario E: AL with trig parameters
Figure 6: Numerical results for scenario F: AL with combo parameters
Figure 7: Numerical results for the misspecified distribution, where the true measurement error is gamma distributed. Predicted errors are (a) two-piece Gaussian distributed or (b) asymmetric Laplace distributed.
Predicted Distribution
TPG
AL
Testing Loss
0.219
0.215
Table 2: Predicted losses for the misspecified gamma distributed errors
Method
HRRR
CP
EasyUQ
TPG
AL
Loss Function
MAE
CRPS
CRPS
CRPS /RS/ACCRUE
CRPS /RS/ACCRUE
1-hour Ahead Testing Loss
1.1536
0.8329
0.8305
0.8324/0.6692/0.7998
0.8312/0.6679/0.7495
Table 3: Predicted losses for temperature forecasts in degrees Celsius.
Figure 8: Uncertainty estimates for HRRR one-hour ahead temperature forecasts for testing data extrapolating in time.
Figure 9: Minimum, median, and maximum testing observations (blue crosses) compared to HRRR One-hour ahead temperature forecasts (black circles), and four uncertainty representations added to the forecasts: conformal prediction (CP), EasyUQ, and ACCRUE with two-piece Gaussian (TPG) and asymmetric Laplace (AL) distributions. Uncertainty representations are shown with 95% and 50% CIs (light and dark shaded regions) and the median (black dash).
Deep neural networks achieve impressive results across diverse applications, yet their overconfidence on unseen inputs necessitates reliable epistemic uncertainty modeling. Existing methods for uncertainty modeling face a fundamental dilemma: Bayesian approaches provide principled estimates but remain computationally prohibitive, while efficient second-order predictors lack rigorous connections between their specific objectives and epistemic uncertainty quantification. To resolve this dilemma, we introduce Dirichlet-approximated possibilistic posterior predictions (DAPPr), a principled framework grounded in possibility theory. We define a possibilistic posterior over parameters, project it to the prediction space via supremum operators, and approximate the projected posterior using learnable Dirichlet possibility functions. This projection-and-approximation strategy yields a simple training objective with closed-form solutions. Despite its simplicity, extensive experiments across diverse benchmarks show that DAPPr achieves competitive or superior uncertainty quantification performance over state-of-the-art second-order predictors while maintaining both principled derivation and computational efficiency. Code is available at https://github.com/MaxwellYaoNi/DAPPr.
Yao Ni, Jeremie Houssineau, Yew-Soon Ong +1
Nanyang Technological University · A*STAR · The University of New South Wales +1
Gaussian Processes (GPs) are a powerful tool for modelling and quantifying uncertainty in functional relationships. However, they require practitioners to make a number of design decisions, such as the choice of the kernel and the observation model. Suboptimal choices can produce misspecified models that do not capture the underlying data generating process. We introduce Predictively Oriented Gaussian Processes (PrO-GPs), which treat predictive uncertainty as the primary inferential target and provide a robust alternative to standard GPs. Although direct computation of a PrO posterior for nonparametric models is intractable, we derive a reduced formulation and practical sampling scheme for efficient computation. Through synthetic and real data experiments, we show that PrO-GPs produce better calibrated predictive distributions under model misspecification compared to standard GP approaches.
Quantifying predictive uncertainty is essential for real world machine learning applications, especially in scenarios requiring reliable and interpretable predictions. Many common parametric approaches rely on neural networks to estimate distribution parameters by optimizing the negative log likelihood. However, these methods often encounter challenges like training instability and mode collapse, leading to poor estimates of the mean and variance of the target output distribution. In this work, we propose the Neural Energy Gaussian Mixture Model (NE-GMM), a novel framework that integrates Gaussian Mixture Model (GMM) with Energy Score (ES) to enhance predictive uncertainty quantification. NE-GMM leverages the flexibility of GMM to capture complex multimodal distributions and leverages the robustness of ES to ensure well calibrated predictions in diverse scenarios. We theoretically prove that the hybrid loss function satisfies the properties of a strictly proper scoring rule, ensuring alignment with the true data distribution, and establish generalization error bounds, demonstrating that the model's empirical performance closely aligns with its expected performance on unseen data. Extensive experiments on both synthetic and real world datasets demonstrate the superiority of NE-GMM in terms of both predictive accuracy and uncertainty quantification.
Yang Yang, Chunlin Ji, Haoyang Li +1
School of Statistics and Data Science, Nankai University, Tianjin, China · Kuang-Chi Institute of Advanced Technology, Shenzhen, China · Department of Computing, The Hong Kong Polytechnic University, Hong Kong SAR, China +1