We are developing a distributed computer system that supports usability and interaction studies, by handling the collection, storage and analysis of usage data, such as that generated by user-computer interaction and associated sensing devices (e.g., cameras). Data sources may be distributed as may be the data repositories and data consumers (other computer processes and human investigators). The system supports dynamic configuration of the entire process, including changes in the goals of the investigation itself. In this paper we describe the system's key features, including a generic and evolvable data transport and processing network, a set of tools for capturing and cleaning usage data, a tool for instrumenting software for data capture, and a system for managing the entire process. We also report on several trials of the system, identifying successes, failures, lessons learned and areas for future development.