Abstract

The data gathered in all kind of web-based systems, which enable users to interact with each other by sharing their knowledge and interests, provides the opportunity to extract social networks that exist between people. The emerging structures are very complex due to the number and type of discovered relations. In the web-based systems, the characteristic element of each interaction between users is that there is always an object that serves as a communication medium between users. This can be e.g. an email sent from one user to another or post at the forum authored by one user and commented by others. Based on these objects and activities that users perform towards them different kinds of relations can be identified. Additional complication appears as the hierarchies between the objects can exist, e.g. a forum consists of one or more groups of topics, each of them contains topics that finally include posts. In this paper, we propose a new method for creation of multi-layered social network based on the data about users activities towards different objects between which the hierarchy can be identified. Due to the new flattening, pre-processing procedure some new layers and new relationships in the multi-layered social network can be identified and further analyzed.