FIGNN: Feature-Specific Interpretability for Graph Neural Network Surrogate Models

TL;DR

FIGNN introduces a feature-specific pooling and regularization approach to improve interpretability of GNN surrogate models in scientific applications, revealing meaningful spatial feature influences while maintaining competitive accuracy.

Contribution

The paper proposes FIGNN, a novel GNN architecture with feature-specific pooling and regularization, enabling interpretable and accurate surrogate modeling for complex physical systems.

Findings

FIGNN achieves competitive predictive accuracy.

FIGNN reveals physically meaningful spatial feature patterns.

FIGNN demonstrates stable and interpretable surrogate modeling.

Abstract

This work presents a novel graph neural network (GNN) architecture, the Feature-specific Interpretable Graph Neural Network (FIGNN), designed to enhance the interpretability of deep learning surrogate models defined on unstructured grids in scientific applications. Traditional GNNs often obscure the distinct spatial influences of different features in multivariate prediction tasks. FIGNN addresses this limitation by introducing a feature-specific pooling strategy, which enables independent attribution of spatial importance for each predicted variable. Additionally, a mask-based regularization term is incorporated into the training objective to explicitly encourage alignment between interpretability and predictive error, promoting localized attribution of model performance. The method is evaluated for surrogate modeling of two physically distinct systems: the SPEEDY atmospheric circulation model and the backward-facing step (BFS) fluid dynamics benchmark. Results demonstrate that FIGNN achieves competitive predictive performance while revealing physically meaningful spatial patterns unique to each feature. Analysis of rollout stability, feature-wise error budgets, and spatial mask overlays confirm the utility of FIGNN as a general-purpose framework for interpretable surrogate modeling in complex physical domains.