The document summarizes the Observation Survey, a tool used to observe and measure visitor behavior in museums. It can be used to: 1) Survey visitor paths, analyze time spent and stops, and identify what attracts or is ignored by visitors. 2) Evaluate exhibits, accessibility, and how visitors use museum services. 3) Evaluate communication and effectiveness of permanent and temporary exhibits. The Observation Survey tool collects real-time data on mobile devices and displays it on a web application for analysis. It aims to evaluate displays and communication, optimize data collection, and train museum staff. Several Italian museums have experimented with the Observation Survey tool.