Flexible Bayesian Model Selection and Model Averaging

Biostatistical seminar with Aliaksandr Hubin, Associate Professor in Statistics and Biostatistics at the Norwegian University of Life Sciences (NMBU), Norway.

Abstract

In this talk, I will introduce a method for model selection and averaging in Bayesian generalized nonlinear regression [1]. Our approach generates nonlinear features hierarchically—similar to deep learning but with even greater flexibility—encompassing most existing statistical learning models as special cases while allowing them to be combined within a single Bayesian model averaging (BMA) framework. Model priors are designed to penalize the complexity of nonlinear features and encourage parsimony. As a result, we often obtain highly interpretable nonlinear models that recover data-generating processes for physical laws [1], logical [2] and fractional [3] polynomials, or governing equations in Sparse Identification of Nonlinear Dynamical Systems (SINDy). When no true data-generating model is feasible, BMA still accounts for model uncertainty, ensuring robust predictive performance.

For Bayesian inference and posterior model probability estimation, we employ a genetically modified mode-jumping Markov chain Monte Carlo (GMJMCMC) algorithm [1,2]. To scale to larger datasets, we also provide subsampling-based MCMC [4] and an Evolutionary Variational Bayes method [5].

I will demonstrate this approach through various applications, accompanied by hands-on examples using the FBMS R package (CRAN link). Examples will include recovering physical laws and SINDy solutions, logic and fractional polynomial regressions, extensions to latent Gaussian nonlinear models, and predictive modeling tasks.

References:

[1] Hubin, Aliaksandr; Storvik, Geir & Frommlet, Florian (2021). Flexible Bayesian Nonlinear Model Configuration. The Journal of Artificial Intelligence Research. ISSN 1076-9757. 72, p. 901–942.

[2] Hubin, Aliaksandr; Storvik, Geir Olve & Frommlet, Florian (2018). A Novel Algorithmic Approach to Bayesian Logic Regression (with Discussion). Bayesian Analysis. ISSN 1936-0975. 15(1), p. 263–311. doi: 10.1214/18-BA1141

[3] Hubin, Aliaksandr; Heinze, Georg & De Bin, Riccardo (2023). Fractional Polynomial Models as Special Cases of Bayesian Generalized Nonlinear Models. Fractal and Fractional. 7(9), p. 1–23. doi: 10.3390/fractalfract7090641

[4] Lachmann, Jon; Storvik, Geir Olve; Frommlet, Florian & Hubin, Aliaksandr (2022). A subsampling approach for Bayesian model selection. International Journal of Approximate Reasoning. ISSN 0888-613X. 151, p. 33–63. doi: 10.1016/j.ijar.2022.08.018

[5] Hauglie Sommerfelt, Philip Sebastian & Hubin, Aliaksandr (2024). Evolutionary variational inference for Bayesian generalized nonlinear models. Neural Computing & Applications. ISSN 0941-0643. p. 1–18. doi: 10.1007/s00521-024-10349-1

Published Mar. 4, 2025 3:47 PM - Last modified Mar. 17, 2025 10:08 AM