  Recent advances in our understanding of the Universe have revolutionized our
view of its structure, composition and evolution. However, these new ideas have
not necessarily been used to improve the teaching of introductory astronomy
students. In this project, we have conducted research into student
understanding of cosmological ideas so as to develop effective web-based tools
to teach basic concepts important to modern cosmology. The tools are intended
for use at the introductory college level. Our research uses several
instruments, including open-ended and multiple choice surveys conducted at
multiple institutions, as well as interviews and course artifacts at one
institution, to ascertain what students know regarding modern cosmological
ideas, what common misunderstandings and misconceptions they entertain, and
what sorts of materials can most effectively overcome student difficulties in
learning this material. These data are being used to create a suite of
interactive, web-based tutorials that address the major ideas in cosmology
using real data. Having students engage with real data is a powerful means to
help students overcome certain misconceptions. Students master the scientific
concepts and reasoning processes that lead to our current understanding of the
universe through interactive tasks, prediction and reflection, experimentation,
and model building.
