With books and manuals, users decide what information 1. they want and when they will acquire it. With training materials, however the writer/instructional designer controls the flow of information and the way in which it is presented. To write training materials requires careful consideration of adult learning principles, the possibilities and limitations of presentation media and, for classroom training, the difference between written and spoken language. A training writer also needs to distill from complex concepts the main points that participants will remember after the training.
Urbick, Dolores. STC Proceedings (1996). Presentations>Education>Instructional Design>Writing