These people might be intelligent, have forceful personalities or very strong ideas about the subject. Quite often, the rest of the class remains silent unless called upon. One reason is because while we are formulating a response in our minds, the conversation continues to move on. The moment is lost and we've kept our insight or questions to ourselves. The on-line classroom is different.
Every student has an equal opportunity to submit ideas, comments and questions.
We can write, revise, revise, revise and then send it to the class. It is never too late to make a point, clarify one or refute one. It was this process that allowed me to learn that I am not stupid. I have ideas and opinions that others value. In the on-line setting, I discovered my voice.