Summary: This contribution is based on the evidence that most psychological practitioners are concerned with the facilitation of change processes. They help people to learn, to develop, or to change patterns of cognitions, emotions, and behaviors. Consequently, they need assessment tools that enable them to represent the essential features of the complex systems they are concerned with, i.e., structure of functioning and dynamics. After some introductory remarks on systemic assessment, we focus on two methods of comprehensive data representation: one of them is used in order to represent the structure of functioning of a system, the other to assess its dynamics. The first one is called “idiographic system modeling” and represents the interrelations between the most important variables of a system by graphical means. The other one is based on a continuously produced flow of data about the functioning of a system and on a continuous screening of dynamic features of this time series (critical fluctuations, degree of synchronization, and stability vs. instability). It is called “real-time monitoring.” Perhaps this methodology can help to bridge the gap between research, usually realized in artificial laboratory settings, and the change processes taking place in practice.