In adaptive design, designers must enable the experience/object to "learn," and users to be able to "teach" the experience/object. So it's a two-way interaction, in which the user wants to adapt the product, to make it useful to him or her. Therefore, the designers must concentrate on enabling this adaptation in order to achieve a useful experience, rather than attempting to direct the experience toward usefulness themselves. Designers shouldn't aim to control, but to enable.