  Interpersonal influence estimation from empirical data is a central challenge
in the study of social structures and dynamics. Opinion dynamics theory is a
young interdisciplinary science that studies opinion formation in social
networks and has a huge potential in applications, such as marketing,
advertisement and recommendations.
  The term social influence refers to the behavioral change of individuals due
to the interactions with others in a social system, e.g. organization,
community, or society in general.
  The advent of the Internet has made a huge volume of data easily available
that can be used to measure social influence over large populations. Here, we
aim at qualitatively and quantitatively infer social influence from data using
a systems and control viewpoint. First, we introduce some definitions and
models of opinions dynamics and review some structural constraints of online
social networks, based on the notion of sparsity. Then, we review the main
approaches to infer the network's structure from a set of observed data.
Finally, we present some algorithms that exploit the introduced models and
structural constraints, focusing on the sample complexity and computational
requirements.

Systems and Control;Social and Information Networks;Systems and Control