Computerized support systems enhancing taskforce performance are being increasingly used in different organizations in the military, emergency response and crisis management fields. Computerized command and control (C2) systems and systems supporting concept development and experimentation (CD&E), training and capability development mostly handle data logged by technical systems, devices and sensors. Organizational demands for improved mission capabilities and reduced budgets impose new requirements on system performance and data content. More information needs to be provided by humans in the field, reporting observations from the evolving course of events in order to enhance possibilities for operational analyses and continuous development of organizational abilities. In this paper, we introduce model-based data collection (MBDC) and describe a method that can improve human datacollection abilities and data quality when using human observers as data collecting sensors in distributed tactical operations. Furthermore, we introduce a tool that can support observers in the field. The network-based observer tool (NBOT) can support human observers in determining what to report, and how and when to report the observation. It is possible to configure NBOT to meet different requirements, for example from a consideration of information needs, the field environment and available budget. We present results and findings from three different use cases.