It is pointed out that a major limitation of graphical user interfaces for simulation is that users such as managers and decision makers need to know too much. The author examines the weaknesses inherent in graphical user interfaces to support these users of simulation for short-term situation assessment and scenario evaluation, a style of problem-solving characteristic of military and factory command-and-control. He then presents Shoptalk, a factory command-and-control system with an interface integrating direct manipulation and natural-language processing, and demonstrates how the Shoptalk style of interaction can overcome these limitations.