# Dropout Inference in Bayesian Neural Networks with Alpha-divergences

arXiv: https://arxiv.org/abs/1703.02914 · HTML: https://mlsanity.com/paper/1703.02914/

## Key facts

- Cited by 28 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 8 Mar 2017.

## Built on by (most cited first, 28 of 28)

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- [BADDr: Bayes-Adaptive Deep Dropout RL for POMDPs](https://mlsanity.com/paper/2202.08884/) (2022)
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- [Laplace Approximation for Bayesian Tensor Network Kernel Machines](https://mlsanity.com/paper/2604.26673/) (2026)
- [Excess risk analysis for epistemic uncertainty with application to variational inference](https://mlsanity.com/paper/2206.01606/) (2022)
- [Beliefs Beyond Posteriors: The Predictive Cost of ELBO Binding](https://mlsanity.com/paper/2605.08446/) (2026)
- [Soft Specialists: α-R'enyi Ensembles for Uncertainty-Aware LLM Post-Training](https://mlsanity.com/paper/2605.27747/) (2026)
- [Uncertainty quantification for trustworthy deep learning: Methods and measures](https://mlsanity.com/paper/2607.28248/) (2026)

## Abstract (arXiv)

To obtain uncertainty estimates with real-world Bayesian deep learning models, practical inference approximations are needed. Dropout variational inference (VI) for example has been used for machine vision and medical applications, but VI can severely underestimates model uncertainty. Alpha-divergences are alternative divergences to VI's KL objective, which are able to avoid VI's uncertainty underestimation. But these are hard to use in practice: existing techniques can only use Gaussian approximating distributions, and require existing models to be changed radically, thus are of limited use for practitioners. We propose a re-parametrisation of the alpha-divergence objectives, deriving a simple inference technique which, together with dropout, can be easily implemented with existing models by simply changing the loss of the model. We demonstrate improved uncertainty estimates and accuracy compared to VI in dropout networks. We study our model's epistemic uncertainty far away from the data using adversarial images, showing that these can be distinguished from non-adversarial images by examining our model's uncertainty.
