I use a mixture of both, however more motivation.
If manipulation is meant in a positive way, for example the demonstration of a procedure in lab or manipulation of certain materials, then I use both manipulation as well as motivation to teach students. Both methods I believe are of extreme importance for the student to succeed. I use motivation in praising the student if they do well, giving them the opportunity to practice as much as possible; encouraging them in any way I can. Manipulation I use by for example demonstrating the use of certain materials or procedures.
@chittenden : Motivation is the influence one has over another using rewards or punishment. As an instructor, I hope that my students realize that I am there for them and that the only reward would be the incredible opportunity to learn information that will be used to further their career goals. I do not use grades as a motivator not as a punishment, however, students are aware that their grades are dependent upon their efforts and abilities to do the work required to "master" the subject.
Manipulation is often used to get students to come to class and get fully engaged in the subject matter. So manipulation by using great examples, variety of activities that keep them coming again and again just to see what will happen in this class is what I do.
