In this paper we propose a framework that characterizes user interaction with webGIS. Furthermore we present a technique to remotely test and evaluate such systems. Our framework does not only include parameters describing the usability of a system, but refers to factors that we argue influence interaction and satisfaction substantially, such as the user's background and previous experience, or the user's computer equipment. We have developed tools and techniques to test webGIS remotely so that users can evaluate the system in their own environment rather than an intrusive laboratory. This remote-testing environment allows us to record parameters such as task completion time, the rate of interactions but also the type of operating system and network connection used during the evaluation. In a case study we captured the interaction of more than 300 users with a system whose purpose was to locate points of interest in a region of Switzerland. The data that was gathered during this remote-evaluation was used to validate and verify the conceptual framework. We have found out that parameters such as the user's experience with similar systems or the type of input device and connection speed significantly influence both the interaction and the user's satisfaction. The tools and the framework that we present in this paper are useful for developers and designers of webGIS, but also for researchers who are interested in evaluating the usability of such systems.