In any distance learning experience, something separates the learner from the instructional resource. That "something" might be distance, or it might be time. Thanks to the online medium, educational activity can take place in spite of geographical barriers or scheduling conflicts.

But separation also creates a dilemma for both teachers and learners. Separation severs a critical feedback loop that we take for granted when we work in a classroom. In the classroom, we learn a lot about how effective we are as teachers just by looking out across the room. We can often tell at a glance who's paying attention and who's distracted, who is confused or bored, and who is ready for more. On the basis of these instant cues, we make adjustments from moment to moment in the way we teach.

Students, too, take instant communication for granted in the classroom. They rely on it to resolve their own uncertainty when they ask questions during a lesson. They use it to test and adjust their understanding when they speak up in class, seeking affirmation or correction.

Unfortunately, instant feedback during instruction is typically the first casualty of the online medium. Even when we use a real-time technology like Internet phone or video conferencing, we lose a lot of the subtle cues that we rely upon in the classroom. The loss is greater when we are using non-visual or silent media like text-based chat, and greater still when we move out of real-time into asynchronous exchange with email or Web-based messaging.