Interaction on human-centric communication platforms: modelling and analysis using algebraic high-level nets and processes

Human-centric communication platforms, like social networks such as Facebook or Twitter, weblogs, Wiki-systems or Apache Wave, are systems that support humans to communicate, collaborate interactively, and exchange content. Over the last years, modern communication systems have evolved to provide different more interactive ways of communication, where several users have the possibility to concurrently contribute to the communication at the same time. These non-sequential ways of communication lead to new requirements for the modelling and analysis of the interactive communication of users on communication platforms, where it does not suffice to model the communication platform itself, but it is also necessary to be able to model scenarios and histories of interactions on a platform. Up to now there are no adequate techniques for the formal modelling of these kinds of communication platforms and the interactions of users on these platforms that could serve as a basis for their formal analysis. In this thesis, in order to close this gap, we present a modelling framework for communication platforms and scenarios that is an integration of Petri net, algebraic data type, process and graph transformation techniques. Within this framework, we obtain main conceptual results concerning communication platforms and scenarios of interactions that rely on technical results concerning the modelling and evolution of algebraic high-level nets and -processes. Based on the formal modelling of communication platforms and scenarios in our integrated framework, we obtain the following main analysis results: Employing general results from the categorical framework of M-adhesive categories, we are able to analyse the independence of different evolutions of communication platforms, and to analyse and synthesise parallel as well as concurrent evolutions of platforms. Based on these main results for the analysis of communication platforms, we develop corresponding technical results that on the conceptual layer allow also the analysis of scenario evolutions, and the investigation of user interactions on communication platforms. Due to our integrated framework, we are also able to analyse the compatibility of scenario and platform evolutions. Further, a comprehensive concept of different levels of abstraction of scenarios allows to investigate a whole set of coinciding scenarios at once, and we show that all concrete realisations of an abstract scenario can be obtained as solutions of a term equation system. The implementation of our algebraic high-level net and process editor (APE) is in progress and will support the modelling and analysis of communication platforms and scenarios using the modelling and analysis results in this thesis. The practical application of all results concerning the modelling and analysis of communication platforms and scenarios are exemplified in the context of the communication platform Apache Wave which serves as a running example throughout the thesis.