Both the analytical toolkit and the studies presented and analysed in the next sections are openly available as part of 
the Open Research Knowledge Graph [35].24 This contributes to future research on the same topic by enabling consultation 
of existing literature in a structured manner and make relevant comparisons (cfr. snapshot in Fig. 2). It will also promote 
the analytical toolkit in the form of vocabulary for reuse.

4.  Using knowledge graphs for explainable machine learning

The AI literature has a long history of working on exploiting structured knowledge for a system’s explainability, start-
ing already from the early knowledge-based systems designed in response of a ﬁrst generation of expert systems unable
Knowledge graphs as tools for explainable machine learning: A survey