After students hear the introduction, they are ready to work on the case. They see a map of the volcano and some questions to help them get started. They can visit any of six different ``sites'' where they can run tests on the mountain to gather evidence for their case.
The intent of the activity in this phase is to get students working right away. They aren't required to read or hear a lot of information, but can leap right into the ``doing'' phases. The map guides students from test group to test group, while each test is fairly straightforward to run. Along the way they can ask for help from experts by clicking on question buttons that are always available on screen.
There are three types of screen students see in this phase: the navigation screen, testing screens, and expert help screens.