Other guides on public speaking focus on how to convey knowledge or understanding. While it is useful to master such informative speech, other goals and strategies are essential for a politician: publicity, for one. To communicate optimism, to rely on material written by others, to speak repeatedly, day in and day out. Above all, politicians need to persuade their audiences. They can use facts or appeal to values, but in the end, they must urge action. Politicians are advocates.