In addition to the eXpresser, the other main student-facing tool is the eGeneraliser. This is the system component that is responsible, among other things, for generating feedback messages for students.

The eGeneraliser comprises a set of modules that take as their input information from eXpresser as students are undertaking tasks, as well as information stored in the MiGen database about students, activities and the tasks themselves. The eGeneraliser generates the most appropriate form of real-time feedback for students by applying a set of rules that combine information about the student's current construction, his/her recent history of actions, and the feedback messages already displayed by the system to the student.

As a student interacts with eXpresser, the eGeneraliser also automatically infers a series of interaction indicators about the student's construction, selected ones of which can then be notified to the teacher via the Teacher Assistance tools. Reasoning about these indicators, the eGeneraliser can make judgements about the suitability of the student's construction for the task at hand, its generality, and how it relates to what the student has done in the past. Based on this, the eGeneraliser can sometimes intervene to help a student.

Unless the intervention is critically important, students are not interrupted to present feedback to them. Instead, interventions are stored as "suggestions" in a box at the bottom of the display. This allows the system to support students without compromising their own exploration of the task.

If students want help from the system, they can open the box to receive feedback. Feedback can take many forms, but in general it aims at making students reflect on what they have done and what they should do next (please click on the image below to see it at full scale).

In some cases, e.g. if the student seems to be stuck or off-task, the system will interrupt them directly to 'nudge' them in the right direction.