Capturing user interface events with aspects

User interface events, resulting from the normal operations of a window-based application, provide crucial information for usability evaluation. Since user interface events are extremely voluminous and rich in detail, automated capture tools are required. With the intent to support usability evaluation in early development phases, such a tool must meet two basic criteria: acquiring relevant usability information at the desirable level of abstraction and adaptable to continuous changes in the user interface. Here, we propose an aspect-oriented approach to capturing user interface events. As the user interacts with an application through its user interface, user interface events occur in various components across the application. Aspects allow capturing select user interface events in a self-contained fashion without imposing undesirable constraints on the target application. We demonstrate in this paper that our approach is a suitable one for early usability evaluation.