Learning PAC-Bayes Priors for Probabilistic Neural Networks

Archive ouverte

Pérez-Ortiz, María | Rivasplata, Omar | Guedj, Benjamin | Gleeson, Matthew | Zhang, Jingyu | Shawe-Taylor, John | Bober, Miroslaw | Kittler, Josef

Edité par CCSD -

Recent works have investigated deep learning models trained by optimising PAC-Bayes bounds, with priors that are learnt on subsets of the data. This combination has been shown to lead not only to accurate classifiers, but also to remarkably tight risk certificates, bearing promise towards self-certified learning (i.e. use all the data to learn a predictor and certify its quality). In this work, we empirically investigate the role of the prior. We experiment on 6 datasets with different strategies and amounts of data to learn data-dependent PAC-Bayes priors, and we compare them in terms of their effect on test performance of the learnt predictors and tightness of their risk certificate. We ask what is the optimal amount of data which should be allocated for building the prior and show that the optimum may be dataset dependent. We demonstrate that using a small percentage of the prior-building data for validation of the prior leads to promising results. We include a comparison of underparameterised and overparameterised models, along with an empirical study of different training objectives and regularisation strategies to learn the prior distribution.

Suggestions

Du même auteur

A PAC-Bayesian Perspective on Structured Prediction with Implicit Loss Embeddings

Archive ouverte | Cantelobre, Théophile | CCSD

38 pages. Many practical machine learning tasks can be framed as Structured prediction problems, where several output variables are predicted and considered interdependent. Recent theoretical advances in structured ...

PAC-Bayes unleashed: generalisation bounds with unbounded losses

Archive ouverte | Haddouche, Maxime | CCSD

International audience. We present new PAC-Bayesian generalisation bounds for learning problems with unbounded loss functions. This extends the relevance and applicability of the PAC-Bayes learning framework, where ...

Progress in Self-Certified Neural Networks

Archive ouverte | Perez-Ortiz, Maria | CCSD

International audience. A learning method is self-certified if it uses all available data to simultaneously learn a predictor and certify its quality with a statistical certificate that is valid on unseen data. Rece...

Chargement des enrichissements...