Decisions Dynamics in ICT systems: the influence of a context-aware and social approach on the multiple criteria decision making processes

In an Information and Communication Technology (ICT) system, information and knowledge have a key role in the development as well as in the evolution of processes. Due to the continuous improvement of the ICT, there are no limits on when, where and how each process has to take place. This condition, if on one hand permits that all the processes can be easily performed, on the other hand it increases the complexity level of each process itself. Furthermore the development of each process is much more complicated considering the concepts of social networking. In fact, taking into consideration the mechanism of social influence and social contagion as well as the capability and knowledge of each individual, the network node is affected, in a positive or in a negative way, not only by the other nodes of the network connected to it but also by its position and importance within the network. Considering an ICT system, there are a lot of processes that can take place within a network. The main focus of my Ph. D. research activity has been to analyse the decision making process taking place in a social network and, in particular, the main features that influence the development of the process itself. In fact, due to events and objectives that an individual, the decision maker (DM), had to face and deal, it becomes necessary to take decisions. In an ICT system, each decision making process is characterised by four main features: dynamism, context-dependence, multiple criteria and social influence. Dynamism expresses the continuous change of the characteristics of both environment and of the decision maker who has to perform the process at each time step. Context-dependence, instead, means the importance of the context, defined as the information that is necessary to describe the situation where a decision maker performs its processes. As expressed before and as a confirmation of the importance of a multiple criteria decision analysis, the paradigm of the decision making process is the evaluation of each alternative on the basis of a set of criteria. In this way the advantages and the drawbacks of each alternative are highlighted. Social influence has to be taken into consideration in the development of the decision making process, because the decision maker performs its process not alone but it is surrounded by other individuals that have a minor or a greater, a positive or a negative, influence on it, leading its decisions near or far from its initial inclination, as a results of social interactions among individuals. These four aspects have to be considered together with the personal features of each decision maker, like, for example, its psychological and psycophysical state. Thus, considering the aspects previously introduced, this Ph. D. dissertation proposes a multiple criteria and context-aware decision making model being able to represent the decision making process of an individual in a social network. This model is able to represent the dynamics of decision taken by an individual within a social network, considering the variation of the context and the influence that the individual perceives from its neighborhood. The behaviour of each individual is represented by a set of parameters, whose variation influences the dynamics of decision within the social network. Successively, applying the same perspective to the process of knowledge transfer and learning, it is possible to consider these processes as individual decision making process where each individual has to decide if accept or not knowledge from its neighboring nodes. In the Ph. D. dissertation the concepts and the analytical instruments provided by the multiple criteria decision analysis (MCDA) are applied to social networks in order to represent as much as possible realistic decision making processes involving individuals that are parts of social networks in different contexts.