Editing Network theory (section)

===Assortative and disassortative mixing===
{{see|Assortative mixing}}
These concepts are used to characterize the linking preferences of hubs in a network. Hubs are nodes which have a large number of links. Some hubs tend to link to other hubs while others avoid connecting to hubs and prefer to connect to nodes with low connectivity. We say a hub is assortative when it tends to connect to other hubs. A disassortative hub avoids connecting to other hubs. If hubs have connections with the expected random probabilities, they are said to be neutral. There are three methods to quantify degree correlations.<ref>M. E. J. Newman (2003). "Mixing patterns in networks". ''Physical Review E''. '''67''' (2): 026126. [[ArXiv (identifier)|arXiv]]:cond-mat/0209450. [[Bibcode (identifier)|Bibcode]]:2003PhRvE..67b6126N. [[Doi (identifier)|doi]]:10.1103/PhysRevE.67.026126. [[PMID (identifier)|PMID]] 12636767. [[S2CID (identifier)|S2CID]] 15186389.</ref>