Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for adaptive educational activities are disclosed. In one aspect, a computer-implemented method includes receiving, by a computing device that is configured to grant a given user access to a first group of activity modules based on a classification of the given user, user data and classification data. The method includes granting the user access to a first activity module and a second activity module, and preventing the user from accessing a third activity module. The method includes receiving interaction data based on the user interacting with the first activity module, and determining that the interaction data indicates an improper classification of the user. Based on the interaction data, the method includes maintaining the classification of the user, granting the user access to a fourth activity module, and preventing the user from accessing the second activity module.