This paper treats only those schools conducted in English. Virtual schools vary in some significant ways. The first is whether or not the courses offered are scheduled for a particular time or can be taken at the convenience of the student. Other schools claim to be scheduled if they require work to be completed within a certain time frame. Unscheduled courses are available at a website and can be accessed whenever the student has time available.
Courses also differ depending upon the immediacy and amount of interaction that occurs.
Synchronous courses use new technologies to provide real-time dialog, sometimes even visual exchanges. Currently few Web courses provide for much of this, though some few use it extensively. Asynchronous courses allow for communication only through email or even snail mail. We will use three terms to describe courses offered through virtual schools. Because of scheduling problems, especially across states and time zones, the largest category of courses are unscheduled, asynchronous courses.