The purpose of this paper is to report on the development of a team performance measurement system capable of supporting the Army's recent initiatives for testing systems and doctrine in synthetic environments. One mechanism for evaluating emerging Army systems and doctrine is the Advanced Warfighting Experiment in which a synthetic theater of war (STOW) environment is created. STOW environments provide a key function in the test and evaluation (T&E) process, yet they pose challenges for effective team performance measurement, an important component for providing feedback to the development process. Challenges include lack of control of task content, requirement to capture performance in near real-time, and the use of multiple observers who must be kept cognizant of ground truth in a complex, dynamic environment so that they can legitimately assess team performance. To address the challenges outlined above, the TRACTs (Tactically Relevant Assessment of Combat Teams) performance measurement system was developed. TRACTs capitalizes on recent work performed by the Navy and Army in the area of team performance measurement. It captures both task-based and team-based performance and is implemented on a computer-based, hand-held data collection device. TRACTs was recently used to evaluate team and task performance during an assessment of employment concepts for the Crusader system. Crusader is a revolutionary weapon system which will be fielded by the Army in 2005. This paper addresses TRACTs design, TRACTs data obtained during the Crusader experiment, and discussions of how these data can be used to augment the T&E process.