To Predict or Not to Predict? Towards reliable uncertainty estimation in the presence of noise
Organizations: Centre for Translation, Localisation and Interpreting Studies, School of Languages, Cultures and Societies, University of Leeds, UK
Abstract
This study examines the role of uncertainty estimation (UE) methods in multilingual text classification under noisy and non-topical conditions. Using a complex-vs-simple sentence classification task across several languages, we evaluate a range of UE techniques against a range of metrics to assess their contribution to making more robust predictions. Results indicate that while methods relying on softmax outputs remain competitive in high-resource in-domain settings, their reliability declines in low-resource or domain-shift scenarios. In contrast, Monte Carlo dropout approaches demonstrate consistently strong performance across all languages, offering more robust calibration, stable decision thresholds, and greater discriminative power even under adverse conditions. We further demonstrate the positive impact of UE on non-topical classification: abstaining from predicting the 10% most uncertain instances increases the macro F1 score from 0.81 to 0.85 in the Readme task. By integrating UE with trustworthiness metrics, this study provides actionable insights for developing more reliable NLP systems in real-world multilingual environments. See https://github.com/Nouran-Khallaf/To-Predict-or-Not-to-Predict
Figures & tables
| Simple | Complex | |||
| Language | #Ex’s | IQR | #Ex’s | IQR |
| ReadMe | ||||
| Arabic | 766 | 9–20 | 533 | 12–33 |
| English | 1,296 | 9–20 | 448 | 13–32 |
| French | 810 | 10–23 | 367 | 14–35 |
| Hindi | 569 | 9–20 | 396 | 11–29 |
| Method | Formulation | Key Characteristics |
| Class probability-based methods | ||
| SR | Top-class softmax probability. | Directly available, but calibration is questionable. |
| SMP | MC Dropout-averaged top-class probability. | Captures disagreement across stochastic passes. |
| ENT | Entropy over softmax probabilities. | Captures prediction ambiguity. |
| ENT-MC | MC Dropout-averaged entropy over probabilities. | Captures ambiguity across stochastic passes. |
| PV | MC Dropout-averaged variance in probabilities. | Captures disagreement across stochastic passes. |
| Metric | Range | Interpretation |
| Uncertainty Discrimination | ||
| ROC-AUC | [0, 1] | Indicates whether incorrect predictions have higher uncertainty. Higher is better. |
| AU-PRC | [0, 1] | Identifies incorrect predictions via uncertainty. Higher is better. |
| Calibration Metrics | ||
| C-Slope | [0, ] | Regression of accuracy on confidence. 1 = underconfident; 1 = overconfident. |
| CITL | Measures the difference between confidence and accuracy. The best value is 0. | |
| Readme Language Class P Std R Std F1 Std Arabic complex 0.77 0.050 0.86 0.058 0.81 0.035 simple 0.90 0.023 0.81 0.067 0.85 0.034 English complex 0.80 0.056 0.79 0.080 0.79 0.036 simple 0.93 0.022 0.93 0.029 0.93 0.013 French complex 0.79 0.047 0.85 0.084 0.81 0.037 simple 0.93 0.032 0.89 0.047 0.91 0.021 Hindi complex 0.79 0.048 0.74 0.128 0.76 0.075 simple 0.83 0.069 0.86 0.044 0.84 0.033 Russian complex 0.75 0.083 0.78 0.113 0.75 0.057 simple 0.90 0.037 0.87 0.067 0.88 0.028 Macro averaged 0.84 0.013 0.84 0.016 0.83 0.014 | Vikidia/Wikipedia Language Class P Std R Std F1 Std Catalan complex 0.72 0.044 0.49 0.137 0.57 0.101 simple 0.62 0.044 0.80 0.075 0.69 0.017 English complex 0.79 0.020 0.62 0.026 0.69 0.021 simple 0.68 0.016 0.83 0.017 0.75 0.015 French complex 0.69 0.006 0.60 0.008 0.64 0.006 simple 0.64 0.005 0.73 0.008 0.68 0.005 Italian complex 0.66 0.017 0.64 0.102 0.65 0.058 simple 0.66 0.049 0.68 0.048 0.66 0.012 Spanish complex 0.68 0.017 0.72 0.007 0.70 0.011 simple 0.71 0.011 0.66 0.024 0.68 0.017 Macro averaged 0.69 0.035 0.68 0.036 0.68 0.040 |
| Metric Pair | AR | EN | FR | HI | RU |
| Uncertainty Discrimination | |||||
| AU-PRC vs ROC-AUC | 0.52 | 0.61 | 0.65 | 0.53 | 0.58 |
| Calibration Metrics | |||||
| CITL vs ECE | -0.39 | -0.61 | -0.55 | -0.27 | -0.32 |
| C-Slope vs CITL | 0.31 | 0.42 | 0.33 | -0.03 | 0.11 |
| C-Slope vs ECE | -0.37 | -0.46 | -0.45 | -0.28 | -0.29 |
| Metric Pair | AR | EN | FR | HI | RU |
| Discrimination vs Calibration | |||||
| AU-PRC vs C-Slope | 0.45 | 0.47 | 0.31 | 0.51 | 0.57 |
| AU-PRC vs CITL | -0.02 | 0.05 | -0.16 | -0.22 | -0.09 |
| AU-PRC vs ECE | -0.03 | -0.07 | 0.03 | 0.00 | -0.03 |
| C-Slope vs ROC-AUC | 0.38 | 0.40 | 0.31 | 0.59 | 0.46 |
| CITL vs ROC-AUC | -0.14 | -0.01 | -0.14 | -0.24 | -0.13 |