The performance method of instruction is bases on the principle that one learns best by doing. Trainees learn physical or mental skills by performing these skills under supervision. An individual learns to write by writing, to swim by swimming, and to drive by driving. This method may be used to teach something as simple as folding a wash cloth or a more complex task such as performing a drill movement. This show-and-tell method has certain advantages, as well as disadvantages, over the lecture method.