Cognitive Network Science: A Review of Research on Cognition through the Lens of Network Representations, Processes, and Dynamics

Table 2

Definitions of network science terms and variables.

Term/variable	Definition
	number of nodes, , in graph
	number of edges, , in graph
network density	ratio of the number of edges to the maximum number of possible edges
	distance,	shortest path between node and node
where
average shortest path length,	average length of shortest path between pairs of nodes
	diameter,	largest shortest path between nodes
closeness centrality		inverse of the sum of the length of the shortest paths between node i and all other nodes in the graph
	degree,	number of edges attached to node
average degree,	average number of edges per node in network
	local clustering coefficient,	number of edges between the neighbors of node divided by the maximum number of edges between those neighbors
where
average clustering coefficient,	average clustering coefficient of nodes in the network
	modularity,	proportion of edges that fall within subgroups of nodes minus the expected proportion if edges were randomly distributed, range
average efficiency,	measure of how efficiently information is exchanged in the network
	largest connected component	largest group of nodes in the network that are connected to each other in a single component
degree distribution,	probability distribution of node degrees in the network
	power-law exponent for the degree distribution
Small world structure	network with short average path lengths and relatively high clustering coefficient (relative to a random graph with similar density)
scale-free network	network with a degree distribution that is power-law distributed