Few students have escaped the experience of hitting on the correct answer to an exam question on the way out of the testing room. Few musicians and actors have not been seized by the panic of a so-called memory slip during public performances. And few of us have not had the embarassment of blocking on a friend’s name when introducing a group of people in quick succession to a newcomer. These distressing experiences all point to the principle that learning and remembering are a waste of time unless there is appropriate access to the stored material at the moment of truth. The ideas to be covered in this chapter all represent ways of dealing with this important problem of retrieval from memory.