Simulation-based learning environments, often called management flight simulators or Microworlds, are excellent tools for giving people without modeling experience an intuitive understanding of complex systems.   Learning environments let them experience the dynamics of complex systems without the hurdle of having to build models "from scratch".  This workshop will deal with the design of learning environments, their user interfaces, underlying models, and workshop formats for experiencing with them.  Special attention will be paid to methods of displaying information to help users understand causes of the behavior they encounter and thereby make better decisions and learn more quickly.  The presenter will show a number of examples from his own work, but is also eager to make the workshop interactive and would like to hear about other people's experiences with learning environments and from people with models they are interested in turning into learning environments.