We Bear in Mind that the object being worked on is going to be ridden in, sat upon, looked at, talked into, activated, operated, or in some other way used by people individually or en masse.

When the point of contact between the product and the people becomes a point of friction, then the... designer has failed.

On the other hand if people are made safer, more comfortable, more eager to purchase, more efficient—or just plain happier— by contact with the product, then the designer has succeeded.

HENRY DREYFUSS, Designing for People, 1955