  Many real-world complex systems including human interactions can be
represented by temporal (or evolving) networks, where links activate or
deactivate over time. Characterizing temporal networks is crucial to compare
such systems and to study the dynamical processes unfolding on them. A
systematic method to characterize simultaneously the temporal and topological
relations of active links (also called contacts or events), in order to compare
different real-world networks and to detect their common patterns or
differences is still missing. In this paper, we propose a method to
characterize to what extent contacts that happen close in time occur also close
in topology. Specifically, we study the interrelation between temporal and
topological properties of contacts from three perspectives: (1) the
autocorrelation of the time series recording the total number of contacts
happened at each time step in a network; (2) the interplay between the
topological distance and interevent time of two contacts; (3) the temporal
correlation of contacts within local neighborhoods beyond a node pair. By
applying our method on 13 real-world temporal networks, we found that
temporal-topological correlation of contacts is more evident in virtual contact
networks than in physical contact ones. This could be due to the lower cost and
easier access of online communications than physical interactions, allowing and
possibly facilitating social contagion, i.e., interactions of one individual
may influence the activity of its neighbors. We also identify different
patterns between virtual and physical networks and among physical contact
networks at, e.g., school and workplace, in the formation of correlation in
local neighborhoods. Detected patterns and differences may further inspire the
development of more realistic temporal network models, that could reproduce
jointly temporal and topological properties of contacts.
