Agent

In the context of a discussion of interactive communication, an "agent" is something that can perform the instructional activity or help the student perform it. An agent is typically a student, a tutor, a tutoring system or a simulated student.

This part is somewhat controversial: In the extreme case, an agent can be a passive medium, such as text or a video, that presents a performance of the activity. For instance, if the instructional activity is solving physics problems, then a worked example, such as the ones shown in a textbook, is an agent.