A significant challenge in understanding the evolution of a software system is coping with the huge amounts of data left behind during the evolution. One strategy for summarizing this data is to visualize its effect on the system’s architecture. Existing tools that implement this strategy often provide mechanisms to filter the data under consideration. However, this filtering is generally limited to showing the evolution over some unbroken sequence of time, for example the changes over the last six months. In this work we present an alternative approach designed to provide a method for examining the net effect of any set of changes on a systems architecture. We also present Motive, a prototype tool that implements this approach, and demonstrate how it can be used to answer questions about software evolution by describing case studies we conducted on two Java systems.