Computer simulations are increasingly recognized as educational tools that facilitate students' learning in a safe environment. However, the way in which the simulations are used can have considerable impact on learning outcomes. Some have argued that exploratory learning is an effective strategy for learning new materials; but others have expressed concern that allowing free exploration may result in less efficient, or even inaccurate, learning and therefore encourage more guided exploration. The purpose of this work is to compare learning outcomes of students using an interactive computer...