There are different kinds of abstraction: Abstraction based on operations and abstraction based on processes and machines. For examples, users should be albe to see the different levels of synthetic events and states for one process, group of processes, virtual machine or for all of them. So it is important to have a mechanism that supports this kind of abstraction in both the event abstraction process and in visualization part. Last week I was working on creating this kind of abstraction. Also I worked on creating proper interface for showing this abstraction.