Inclusion of Domain-Knowledge into GNNs using Mode-Directed Inverse Entailment
This addresses the challenge of integrating structured domain knowledge into neural networks for improved performance in relational data tasks, representing an incremental advancement over existing techniques.
The paper tackles the problem of incorporating multi-relational domain knowledge into Graph Neural Networks (GNNs) by introducing BotGNNs, which use mode-directed inverse entailment to transform logical background knowledge into graph structures, resulting in significantly better performance than GNNs without knowledge and other knowledge-inclusion methods on real-world datasets.
We present a general technique for constructing Graph Neural Networks (GNNs) capable of using multi-relational domain knowledge. The technique is based on mode-directed inverse entailment (MDIE) developed in Inductive Logic Programming (ILP). Given a data instance $e$ and background knowledge $B$, MDIE identifies a most-specific logical formula $\bot_B(e)$ that contains all the relational information in $B$ that is related to $e$. We represent $\bot_B(e)$ by a "bottom-graph" that can be converted into a form suitable for GNN implementations. This transformation allows a principled way of incorporating generic background knowledge into GNNs: we use the term `BotGNN' for this form of graph neural networks. For several GNN variants, using real-world datasets with substantial background knowledge, we show that BotGNNs perform significantly better than both GNNs without background knowledge and a recently proposed simplified technique for including domain knowledge into GNNs. We also provide experimental evidence comparing BotGNNs favourably to multi-layer perceptrons (MLPs) that use features representing a "propositionalised" form of the background knowledge; and BotGNNs to a standard ILP based on the use of most-specific clauses. Taken together, these results point to BotGNNs as capable of combining the computational efficacy of GNNs with the representational versatility of ILP.