Visualization of users' activities in a specific environment

Evaluation of user interface design is usually based on usability testing methods. In this paper we analyzed and described the user behavior in the form of the user model. The user model is built on a data set which was acquired through observation of user behavior. The criterion we use for the evaluation of the usability of interface design is the user cognitive load. We present different tools for visualization, simulation and easier analysis of the user model. Because each of the methods and tools presented use only part of the user model, in the end we present methods on how to use the complete user model to correctly describe user behavior. In order to understand such a complex model we need to have a proper visualization tool. The concept of such a visualization tool is presented at the end of this paper. © 2007 IEEE.