This paper describes a framework of methods for the measurement and evaluation of users' performance in interaction with a web-GIS. The framework involves testing of a system with real-world users, streaming of the user's screen during the evaluation and the analysis of web-server log files after the evaluation. We have developed and tested this method within a project called RIV together with real-world users that are using a web-GIS. We found out that users have different strategies when interacting with a web-GIS that offers different manners of interaction. The findings that we present in this paper are useful for developers and designers of web-GIS and can help improving such systems.