The design of "Probability Explorer" was inspired by: lack of research-based elementary probability software; constructivist principles for designing computer microworlds; and research on children's probabilistic reasoning. Discussion includes the inspirational and theoretical basis for design; conceptualizing the "Probability Explorer"…

"Bohr's Atomic Model" is a small interactive multimedia program that introduces the viewer to a simplified model of the atom. This interactive simulation lets students build an atom using an atomic construction set. The underlying design methodology for "Bohr's Atomic Model" is model-centered instruction, which means the central model of the…