Social networks that change over time

Consider your group of closest friends. How has that group changed over the last year? The last 5 years? The last 10?

Many social relationships and other types of data that can be represented using networks evolve over time. Friendships drift away and forge as people move, graduate from school, get married, change jobs, travel, or pass away. Animals migrate with changes in season, changes in climate, and human activity encroaching on grazing lands. Sales patterns across stores can be interrupted by new stores in the area, movements of population, and major world events such as COVID-19 or the Ukraine conflict.

In the next sections, we’ll explore dynamic networks, whose structure changes over time. As network structure changes, so do many important properties related to information/disease flow and partitioning of the network.

Friendship networks

Many social network platforms allow friendship groups to evolve and even encourage...