Discusses the evolution of constructivist learning environments and examines the collaboration of simulated software models, virtual environments, and evolving mental models via immersion in artificial realities. A sidebar gives a realistic example of a student navigating through cyberspace. (JMV)

Reports on a pilot study that examined use by sixth-grade students in Costa Rica of a mathematical microworld written in LOGO. The investigation had three phases: (1) open exploration of the microworld; (2) group discussion and sharing of hypotheses; and (3) guided discovery and problem solving. (Contains 11 references.) (SLW)