7. Our advice

When it comes to characterizing external media (EM), be as evasive as possible; take a step back so as not to miss out on innovative solutions.

For example, in the case of the "designer desk lamp", one of the external environments concerns the user. He must switch the light point on and off. If you characterize the external environment as "the user", then all options are possible:

• use the hand, one finger, two fingers ;

• use voice, eyes, clap ;

• use the foot, etc.