Table 2 Key term and measure definitions in relation to this network
Term | Definition | Information this provides about the node or network | Significance in this network | Example or value in this network |
|---|---|---|---|---|
Foundational | ||||
 Node | An element of a network | Identifies different components within a system | Identifies a pertinent aspect of a case presentation as determined by one or more participants | Obesity |
 Link | A association (direction specific) between any pair of nodes | Identifies relationships of influence within a system | Identifies a connection between two nodes that is considered relevant to the case presentation determined by one or more of participants | Alcohol intake to Liver |
 Path | A series of links connecting any pair or group of nodes | Identifies a sequence of connections between two or more elements | Identifies a sequence of relationships between two or more nodes as determined by one or more participants | Increased cortisol to sympathetic nervous system activation to social anxiety to excessive sweating |
 Cluster or Community | A substructure or clique of nodes that are more closely connected to each other compared with nodes outside the subgroup | Identifies well connected cliques within the network, revealing underlying network structure | Establishes the node subgroups as identified by the participants | Green cluster (nervous system, flat mood / depression, fatigue, low motivation, antidepressant medication, headaches, low serotonin) |
Node level measures | ||||
 Degree | The number of links (in or out) that a node has | Identifies nodes deemed most connected with other nodes | Establishes the nodes the practitioners deemed most interactive within the network | High degree: diet, Low degree: loose stools |
 Average degree | The average number of links across all nodes | Establishes the average number of links across the nodes | Provides a mid-point from which the number of links each node has can be compared against | Average = 3.05 (with variation between one and 36) |
 Distance | The number of links on the shortest path between two nodes | Detects the minimum number of steps influence needs to travel | Establishes the intermediate steps for influence to spread between two nodes, as identified by the participants | Indoor job to compromised vitamin D status to flat mood / depression to OR alcohol intake to liver to reduced fat metabolism to oxidative stress |
 Betweenness centrality | How often a node appears on the shortest path between other pairs of nodes | Measures the number of paths that pass through a particular node | Demonstrates the value of each nodes in terms of its potential to interact with others as determined by the participants | Dysbiosis is on the shortest path between: diet & bloating with cramping; gas production & gut fermentation; toxin recycling & halitsosis Flat mood = 2880 Obesity = 2348 Dysbiosis = 2080 Systemic inflammation = 1648 Liver = 1248 |
 Clustering co-efficient | The number of links a node has divided by the total number of possible links. The highest possible value is 1 (where a node is linked to all other node) | Along with the mean shortest path, the clustering co-efficient can indicate a ‘small-world’ effect, and signifies how embedded nodes are within their neighbourhood | Denotes the extent to which nodes are linked within the network | Average clustering co-efficient = 0.114 |
 Eigenvector centrality | Measures the value of each nodes, based on the number of links it has, and the number of links the nodes it connected to has, and so on across the network | A measure of the influence of an element within the network | Denotes the extent to which well-linked nodes are connected to other well-linked nodes | Liver (0.39), hypertension (0.41), systemic inflammation (0.48), dysbiosis (0.60), obesity (0.68), and flat mood / depression (1) |
Network level measures | ||||
 Diameter | The shortest pathway between the two most distant nodes | Provides a measure of the parameters of the network | A measure of how tightly the nodes in the network are linked, as identified by the participants | Diameter = 9 |
 Average path length | The average of the shortest path between all pairs of nodes | The average minimum number of links between all pairs of nodes | Indication of the ease with which change can move across the system | Average path length = 3.71 |
 Average clustering co-efficient | The average of the clustering co-efficient for all nodes | Averaged across all nodes, the proportion of nodes with a direct link to each node, divided by the total number of nodes identified in the network | A measure of how connected the network is | Average clustering co-efficient = 0.114 |
 Modularity | A measure of the extent the network decomposes into subgroups or cliques | Reveals underlying layers of structure within the network | Within communities denser interactional possibilities exist, plus reveals potential sub-structures as identified by the participants | 6 communities detected with between 12 to 33 elements each Modularity score = 0.40 |