I know from being both a student and teacher myself that it is important to teach to student's individual styles. In an online environment, this is quite a difficult task. Not only do you not meet your students, but you don't see them to get visual clues of learning. I know in some of the chapters there are PPT's that go along with the chapter that can help those students who need to see information. Other teachers are also incorporate other visual learning such as webcasts, etc. I think these will help a variety of learners.
