Simulation environments allow people to practice skills such as setting up and defending networks. If we can record informative traces of activity in these online environments and draw accurate inferences about trainee capabilities, then we can provide evidence-based guidance on performance, assess mission readiness, optimize training schedules, and refine training modules. April Galyardt, a machine learning research scientist with Carnegie Mellon University's Software Engineering Institute, discusses efforts to develop a new approach to assessing the skills of the cybersecurity workforce.