This report is Deliverable D9.6 of the SSHOC project. It provides a precondition for subsequent reports D9.7 (Design and Planning of a Knowledge Graph), and D9.9 (Production of a user validated Knowledge Graph). Knowledge graphs are infrastructural tools, in the form of models of knowledge in a substantive domain that connect otherwise isolated silos of information about, for example, publications, data-sets, events, people, tools, etc.