The Causality Lab is a virtual environment meant to simulate the science of causal discovery. Instructors (and students) can author exercises that contain a "true" but hidden causal model which students must then discover.
Like real scientists, however, the students do not get to see the truth directly. Instead, they must set up experiments, collect data, create hypotheses, and compare the predictions made by their hypotheses to the results of these experiments. In so doing, they will learn why association does not prove causation, why statistical tests are crucial to causal science, and why randomized trials are such a powerful tool in causal discovery.