Epistemic Learning from Imprecise Annotation
Organizations: Epistemic Intelligence & Computation Lab, College of Computing & Data Science, Nanyang Technological University, Singapore
Abstract
Imprecise annotations may support several plausible labelling distributions, yet learning methods often resolve this ambiguity into a single predictive distribution. This can obscure what the annotation evidence leaves unresolved. We introduce epistemic learning from credal supervision, a framework that uses convex sets of plausible labelling distributions, called credal sets, as supervision and learns sets of predictive distributions. We instantiate the framework with the pessimistic--optimistic credal classifier (POCC), which combines a shared backbone with two classification heads trained to minimise worst-case and best-case losses over the supervision sets. Their outputs define a predictive credal set whose spread provides an uncertainty score. We also show how credal labels can be obtained through a simple relaxation of existing probabilistic labels, reducing commitment to their precise probability assignments. This construction admits closed-form inner optimisation under cross-entropy loss, enabling efficient training. Assuming the supervision sets contain the true conditional label distributions, and other regularity assumptions, we establish a finite-sample generalisation bound for the averaged predictor with an explicit penalty for supervision imprecision. We evaluate POCC using human annotator disagreement and teacher predictions, alongside label smoothing as a controlled proxy for annotation imprecision. Across these settings, POCC achieves a favourable balance of predictive accuracy, calibration, and uncertainty-based selective classification versus competitive baselines.
Figures & tables
| Method | ACC | ECE | AUARC | BQS |
|---|---|---|---|---|
| EDL | ||||
| LbBnn | ||||
| Decali | ||||
| DAPPr | ||||
| Ours | ||||
| MCDO |
| Method | CIFAR-10 | CIFAR-100 | ||||||
| ACC | ECE | AUARC | BQS | ACC | ECE | AUARC | BQS | |
| EDL | ||||||||
| LbBnn | ||||||||
| Decali | ||||||||
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| Ours | ||||||||
| Method | CIFAR-10 | CIFAR-100 | ||||||
| ACC | ECE | AUARC | BQS | ACC | ECE | AUARC | BQS | |
| EDL | ||||||||
| LbBnn | ||||||||
| Decali | ||||||||
| DAPPr | ||||||||
| Ours | ||||||||
Appendix figures & tables21 assets
Supplementary material from the paper’s appendix.
Appendix
| Hyperparameter | CIFAR-10H | MiceBone | TreeVersity |
|---|---|---|---|
| Backbone | ResNet-18 | DenseNet-121 | DenseNet-121 |
| Classes | 10 | 3 | 6 |
| Input size | |||
| Batch size | 128 | 128 | 128 |
| Epochs | 150 | 60 | 60 |
| Learning rate | 0.1 | 0.00001 | 0.00001 |
| Hyperparameter | CIFAR-10 | CIFAR-100 |
|---|---|---|
| Backbone | ResNet-18 | WRN-28-4 |
| Classes | 10 | 100 |
| Input size | ||
| Batch size | 128 | 128 |
| Epochs | 200 | 200 |
| Learning rate | 0.1 | 0.1 |
| Component | Specification |
|---|---|
| CPU | Intel Core Ultra 24C/24T, 5.8GHz Max, 36MB L3 Cache |
| GPU | NVIDIA GeForce RTX 5090 (32 GB GDDR7) |
| RAM | 192 GB DDR4 ECC DIMM |
| MiceBone Dataset | TreeVersity Dataset | |||||||
|---|---|---|---|---|---|---|---|---|
| Method | ACC | ECE | AUARC | BQS | ACC | ECE | AUARC | BQS |
| EDL | ||||||||
| Decali | ||||||||
| DAPPr | ||||||||
| Ours | ||||||||
| DE | ||||||||
| Method | CIFAR-10 | CIFAR-100 | ||||||
| ACC | ECE | AUARC | BQS | ACC | ECE | AUARC | BQS | |
| Teacher: ResNet-20 | ||||||||
| EDL | ||||||||
| LbBnn | ||||||||
| Decali | ||||||||
| DAPPr | ||||||||
| Method | CIFAR-10 | CIFAR-100 | |||||||
| ACC | ECE | AUARC | BQS | ACC | ECE | AUARC | BQS | ||
| EDL | |||||||||
| LbBnn | |||||||||
| Decali | |||||||||
| DAPPr | |||||||||
| Ours | |||||||||
| Method | CIFAR-10 | CIFAR-100 | ||||||
| ACC | ECE | AUARC | BQS | ACC | ECE | AUARC | BQS | |
| Teacher: ResNet-20 | ||||||||
| EDL | ||||||||
| LbBnn | ||||||||
| Decali | ||||||||
| DAPPr | ||||||||
| Method | CIFAR-10H | MiceBone | TreeVersity | |||||||||
| ACC | 1-ECE | AUARC | BQS-ST | ACC | 1-ECE | AUARC | BQS-ST | ACC | 1-ECE | AUARC | BQS-ST | |
| EDL | ||||||||||||
| LbBnn | – | – | – | – | – | – | – | – | ||||
| Decali | ||||||||||||
| DAPPr | ||||||||||||
| Ours | ||||||||||||
| Method | CIFAR-10 | CIFAR-100 | |||||||
| ACC | 1-ECE | AUARC | BQS-ST | ACC | 1-ECE | AUARC | BQS-ST | ||
| ResNet-20 | EDL | ||||||||
| LbBnn | |||||||||
| Decali | |||||||||
| DAPPr | |||||||||
| Ours | |||||||||
| Method | CIFAR-10 | CIFAR-100 | |||||||
| ACC | 1-ECE | AUARC | BQS-ST | ACC | 1-ECE | AUARC | BQS-ST | ||
| EDL | |||||||||
| LbBnn | |||||||||
| Decali | |||||||||
| DAPPr | |||||||||
| Ours | |||||||||
| Method | ACC | ECE | AUARC | BQS | BQS-ST |
| CIFAR-10H | |||||
| EDL | |||||
| LbBnn | |||||
| Decali | |||||
| DAPPr | |||||
| Ours | |||||
| Method | ACC | ECE | Sp(EU,CE) | BQS | BQS-ST | |
|---|---|---|---|---|---|---|
| CIFAR-10H | EDL | |||||
| LbBnn | ||||||
| Decali | ||||||
| DAPPr | ||||||
| Ours | ||||||
| MCDO |
| Method | CIFAR-10 | CIFAR-100 | ||||||||
| ACC | ECE | Sp(EU,CE) | BQS | BQS-ST | ACC | ECE | Sp(EU,CE) | BQS | BQS-ST | |
| Teacher: ResNet-20 | ||||||||||
| EDL | ||||||||||
| LbBnn | ||||||||||
| Decali | ||||||||||
| DAPPr | ||||||||||
| Method | CIFAR-10 | CIFAR-100 | ||||||||
| ACC | ECE | Sp(EU,CE) | BQS | BQS-ST | ACC | ECE | Sp(EU,CE) | BQS | BQS-ST | |
| EDL | ||||||||||
| LbBnn | ||||||||||
| Decali | ||||||||||
| DAPPr | ||||||||||
| Metric | CIFAR-10H | MiceBone | TreeVersity |
|---|---|---|---|
| MMI | |||
| H-Diff |
| ShuffleNetV2-0.5x | ResNet-20 | MobileNetV2-x0-5 | ||||
|---|---|---|---|---|---|---|
| Dataset | MMI | H-Diff | MMI | H-Diff | MMI | H-Diff |
| CIFAR-10 | ||||||
| CIFAR-100 | ||||||
| Dataset | Smoothing | MMI | H-Diff |
|---|---|---|---|
| CIFAR-10 | 0.05 | ||
| 0.10 | |||
| 0.15 | |||
| 0.20 | |||
| CIFAR-100 | 0.05 | ||
| 0.10 |
| SVHN | Places | FMNIST | ImageNet | |
|---|---|---|---|---|
| EDL | ||||
| Decali | ||||
| DAPPr | ||||
| Ours | ||||
| Our-Ens | ||||
| MCDO |
| SVHN | Places | FMNIST | ImageNet | |
|---|---|---|---|---|
| EDL | ||||
| Decali | ||||
| DAPPr | ||||
| Ours | ||||
| Our-Ens | ||||
| MCDO |
| SVHN | Places | FMNIST | ImageNet | |
|---|---|---|---|---|
| EDL | ||||
| Decali | ||||
| DAPPr | ||||
| Ours | ||||
| Our-Ens | ||||
| MCDO |