Vendredi 31 novembre 2020, à 14h, en salle 26-00/332, Jussieu
Online social networks are constantly growing in popularity. They enable users to interact with one another and mapping their relations to the virtual world. Users utilize social media platforms as a mean for a rich variety of activities, such as share and exchange information, create relations, and others. Such online human interactions take place within a dynamic environment where we can observe and distinguish many qualities related to relations between users, concerning influential, trusted or popular individuals. In this talk, we will focus on the qualities of users connected to four important concepts: influence, reputation, trust, and popularity, in the scope of SNA for influence modelling. We will examine some of the existing works utilizing these notions and emphasize the most important features that these concepts should include in order to measure them based on the SNA information. Using the notions, we will concentrate on a practical model for influence estimation, called Action-Reaction Influence Model (ARIM). This model considers the type, quality, quantity, and frequency of actions performed by users in SN, and is adaptive to different SN types. Furthermore, we will discuss a notion not yet explored much in SNA discipline — micro-influence, which targets new phenomena of users with a small but highly involved audience, who are observed to be still highly impactful. Finally, we will focus on the quantification of influence over time and representation of influence causal effect. Particularly, we will consider a specific kind of SN – citation network, which is highly time-sensitive. Accordingly, we will discuss another influence estimation model, which determines influence during a particular time period between communities within time-dependent citation networks.