Simulations have become core supports for learning in the digital age. For example, economists, mathematicians, and scientists employ simulations to model complex phenomena. Learners, too, are increasingly able to take advantage of simulations to understand complex systems. Simulations can display phenomena that are too large or small, fast or slow, or dangerous for direct classroom investigations. The affordances of simulations extend students' opportunities to engage in deep, extended problem solving. National and international studies are providing evidence that technologies are enriching curricula, tailoring learning environments, embedding assessment, and providing tools to connect students, teachers, and experts locally and globally. This chapter describes a portfolio of research and development that has examined and documented the roles that simulations can play in assessing and promoting learning, and has developed and validated sets of simulation-based assessments and instructional supplements designed for formative and summative assessment and customized instruction.
