Summary

• A graph is made of nodes and edges, which we will use to represent variables and relations between them
• A DAG is an acyclic graph and will be useful for representing ‘causal’ relationships between variables
• Neighbouring nodes on an undirected graph will be useful represent dependent variables.
• A graph is singly-connected if there is only one path from any node to any other - otherwise the graph is multiply-connected.
• A Clique is group of nodes all of which are connected to each other
• The adjacency matrix is a machine-readable description of a graph. Powers of the adjacency matrix give information on the paths between nodes.