Learning in Gaussian Process models occurs through the adaptation of hyperparameters of the mean and the covariance function. The classical approach entails maximizing the marginal likelihood yielding fixed point estimates (an approach called \textit{Type II maximum likelihood} or ML-II). An alternative learning procedure is to infer the posterior over hyperparameters in a hierarchical specification of GPs we call \textit{Fully Bayesian Gaussian Process Regression} (GPR). This work considers two approximation schemes for the intractable hyperparameter posterior: 1) Hamiltonian Monte Carlo (HMC) yielding a sampling-based approximation and 2) Variational Inference (VI) where the posterior over hyperparameters is approximated by a factorized Gaussian (mean-field) or a full-rank Gaussian accounting for correlations between hyperparameters. We analyze the predictive performance for fully Bayesian GPR on a range of benchmark data sets.

本文介绍了高斯过程模型中两种推断超参数后验分布的方法，一种是哈密顿蒙特卡罗（HMC）求解采样近似，另一种是变分推断（VI），其中超参数后验分布被近似为一个因子化的高斯分布或全秩高斯分布，该文分析了完全贝叶斯高斯过程回归在多个基准数据集上的预测性能。

高斯过程全贝叶斯回归的近似推理