Some of the most promising developments in presentation technologies is are those that help students understand complex processes and models.
Some publishers now bundle multimedia CD-ROMs with the instructor's version of textbooks.
On the other hand, some faculty members are developing their own presentations where no such resource is available. Robert Hodson, biology , reported that he makes extensive use of the CD-ROMs that accompany the instructor's edition of some textbooks used in introductory biology classes. Hodson added that helping students understand complex processes like DNA replication, muscle contraction, or photosynthesis was very time-consuming. I used to have to draw things on overheads or the board, then erase and re-draw repetitively. Now, I project an animation of the process for my students as I'm explaining it to them.