The field of explainable artificial intelligence (XAI) attempts to develop methods that provide insight into how complicated machine learning methods make predictions. Many methods of explanation have focused on the concept of feature attribution, a decomposition of the model's prediction into individual contributions corresponding to each input feature. In this work, we explore the problem of feature attribution in the context of Gaussian process regression (GPR). We take a principled approach to defining attributions under model uncertainty, extending the existing literature. We show that although GPR is a highly flexible and non-parametric approach, we can derive interpretable, closed-form expressions for the feature attributions. When using integrated gradients as an attribution method, we show that the attributions of a GPR model also follow a Gaussian process distribution, which quantifies the uncertainty in attribution arising from uncertainty in the model. We demonstrate, both through theory and experimentation, the versatility and robustness of this approach. We also show that, when applicable, the exact expressions for GPR attributions are both more accurate and less computationally expensive than the approximations currently used in practice. The source code for this project is freely available under MIT license at https://github.com/KurtButler/2024_attributions_paper.

解释性人工智能的研究领域试图开发提供复杂机器学习方法如何进行预测的见解的方法。在这项工作中，我们探讨了高斯过程回归（GPR）背景下的特征归因问题，并在现有文献的基础上以原则性的方法定义了特征归因。我们展示了尽管GPR是一种高度灵活的非参数方法，但我们可以导出解释性的闭式表达式用于特征归因。使用Integrated Gradients作为归因方法时，我们表明GPR模型的归因也符合高斯过程分布，从而量化了由于模型的不确定性而产生的归因的不确定性。我们通过理论和实验证明了这种方法的多功能性和稳健性。我们还表明，在适用的情况下，GPR归因的精确表达式比目前在实践中使用的近似方法更准确且计算成本更低。

高斯过程的可解释学习