Credal Wrapper for Uncertainty Modelling in Sparse Geological Data
Abstract
Machine learning models for mineral exploration are trained on a few hundred sparse, expensive samples and used to decide where to drill next, so their epistemic uncertainty (EU), the part that more data could remove, matters as much as their predictions. Yet EU cannot be measured on real data, because the counterfactual that defines it is never observed, so estimators are graded by proxies such as out-of-distribution detection and calibration. We contribute a general simulation protocol that makes EU directly computable for a given model and can grade any EU estimator. It separates two estimands the literature conflates, reducible error and estimator spread, builds an oracle reference for each in a synthetic prospectivity field sampled by clustered drilling surveys, and compares uncertainty measures of an identical ensemble within each simulated world. We use it to ask when credal (imprecise-probability) measures are more faithful than Bayesian model averaging (BMA) in the sparse, low-class regime of geological classification. The credal interval width recovers the epistemic ordering better than BMA when members are few, confirming the small-ensemble advantage reported for credal wrappers; the advantage vanishes by M = 10 and reverses at M = 40. Secondly, the choice of credal functional matters more than the choice between credal and BMA. Lastly, the credal advantage does not widen as training data are thinned, so it compensates for few posterior samples rather than few data. On real drill-hole geochemistry from South Australia, a resampling oracle reproduces the first finding. The protocol applies to any EU estimator whose data-generating process can be simulated.
Related
- Empowering Bayes with sources of uncertainty: from confidence modelling to sparse estimation
- Empowering Bayes with sources of uncertainty: from confidence modelling to sparse estimation
- Credal Large Language Models for Semantic Commitment under Uncertainty
- Computing Robustness to Sparse Diagonal Uncertainty
- A Goal-Oriented Bayesian Experimental Design to Reduce Uncertainty in Sparse-Angle X-ray Computed Tomography
BibTeX
@misc{jeevankumar2026credal,
title = {{Credal Wrapper for Uncertainty Modelling in Sparse Geological Data}},
author = {David Jeevankumar and Maryam Sultana and Alexander D. Rast and Fabio Cuzzolin},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.14527},
eprint = {2611.14527},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.14527},
note = {CC BY-SA 4.0},
}
RIS
TY - UNPB
TI - Credal Wrapper for Uncertainty Modelling in Sparse Geological Data
AU - David Jeevankumar
AU - Maryam Sultana
AU - Alexander D. Rast
AU - Fabio Cuzzolin
PY - 2026
DA - 2026/11/01
PB - arXiv
DO - 10.48550/arxiv.2611.14527
UR - https://arxiv.org/abs/2611.14527
AB - Machine learning models for mineral exploration are trained on a few hundred sparse, expensive samples and used to decide where to drill next, so their epistemic uncertainty (EU), the part that more data could remove, matters as much as their predictions. Yet EU cannot be measured on real data, because the counterfactual that defines it is never observed, so estimators are graded by proxies such as out-of-distribution detection and calibration. We contribute a general simulation protocol that makes EU directly computable for a given model and can grade any EU estimator. It separates two estimands the literature conflates, reducible error and estimator spread, builds an oracle reference for each in a synthetic prospectivity field sampled by clustered drilling surveys, and compares uncertainty measures of an identical ensemble within each simulated world. We use it to ask when credal (imprecise-probability) measures are more faithful than Bayesian model averaging (BMA) in the sparse, low-class regime of geological classification. The credal interval width recovers the epistemic ordering better than BMA when members are few, confirming the small-ensemble advantage reported for credal wrappers; the advantage vanishes by M = 10 and reverses at M = 40. Secondly, the choice of credal functional matters more than the choice between credal and BMA. Lastly, the credal advantage does not widen as training data are thinned, so it compensates for few posterior samples rather than few data. On real drill-hole geochemistry from South Australia, a resampling oracle reproduces the first finding. The protocol applies to any EU estimator whose data-generating process can be simulated.
ER -