The diagram is made up of vertices (cases) and edges (relationships). The relationships between cases are labelled and there could be isolated cases in this type of sociogram.In this example, the sociogram is based on a group of interview participants. The diagram shows that: Mary is the only connection between Barbara and James' groups of connections. William and Charles are connected to each other, but are not a part of the broader network. Robert is an isolated case, with no connections to any other interview participants.