EXplainable Neural-Symbolic Learning (X-NeSyL) methodology to fuse deep learning representations with expert knowledge graphs: The MonuMAI cultural heritage use case

Natalia Díaz-Rodríguez (1, 2, 3, 4) , Alberto Lamas (2, 3) , Jules Sanchez (1) , Gianni Franchi (1) , Ivan Donadello (5) , Siham Tabik (3, 2) , David Filliat (1, 4) , Policarpo Cruz (6) , Rosana Montes (6) , Francisco Herrera (3, 2, 7)

1 U2IS - Unité d'Informatique et d'Ingénierie des Systèmes
2 DECSAI - Department of Computer Science and Artificial Intelligence
3 DaSCI - Instituto Andaluz Interuniversitario en Data Science and Computational Intelligence
4 Flowers - Flowing Epigenetic Robots and Systems
5 Free University of Bozen-Bolzano
6 UGR - Universidad de Granada = University of Granada
7 King Abdulaziz University

The latest Deep Learning (DL) models for detection and classification have achieved an unprecedented performance over classical machine learning algorithms. However, DL models are black-box methods hard to debug, interpret, and certify. DL alone cannot provide explanations that can be validated by a non technical audience such as end-users or domain experts. In contrast, symbolic AI systems that convert concepts into rules or symbols-such as knowledge graphs-are easier to explain. However, they present lower generalisation and scaling capabilities. A very important challenge is to fuse DL representations with expert knowledge. One way to address this challenge, as well as the performance-explainability trade-off is by leveraging the best of both streams without obviating domain expert knowledge. In this paper, we tackle such problem by considering the symbolic knowledge is expressed in form of a domain expert knowledge graph. We present the eXplainable Neural-symbolic learning (X-NeSyL) methodology, designed to learn both symbolic and deep representations, together with an explainability metric to assess the level of alignment of machine and human expert explanations. The ultimate objective is to fuse DL representations with expert domain knowledge during the learning process so it serves as a sound basis for explainability. In particular, X-NeSyL methodology involves the concrete use of two notions of explanation, both at inference and training time respectively: 1) EXPLANet: Expert-aligned eXplainable Part-based cLAssifier NETwork Architecture, a compositional convolutional neural network that makes use of symbolic representations, and 2) SHAP-Backprop, an explainable AI-informed training procedure that corrects and guides the DL process to align with such symbolic representations in form of knowledge graphs. We showcase X-NeSyL methodology using MonuMAI dataset for monument facade image classification, and demonstrate that with our approach, it is possible to improve explainability at the same time as performance.

Mots clés: Explainable Artificial Intelligence; Deep Learning; Neural-symbolic learning; Expert Knowledge Graphs; Compositionality; Part-based Object Detection and Classification

Domaines: Robotique [cs.RO]

Natalia Díaz-Rodríguez, Alberto Lamas, Jules Sanchez, Gianni Franchi, Ivan Donadello, et al.. EXplainable Neural-Symbolic Learning (X-NeSyL) methodology to fuse deep learning representations with expert knowledge graphs: The MonuMAI cultural heritage use case. Information Fusion, 2021, ⟨10.1016/j.inffus.2021.09.022⟩. ⟨hal-03379551⟩