Don Norman

If the system lets you make the error, it is badly designed. And if the system induces you to make the error, then it is really badly designed.

Good design is actually a lot harder to notice than poor design, in part because good designs fit our needs so well that the design is invisible.

The best products do two things well: features and details. Features are what draw people to the product. Details are what keep them there.

The problem is not that there are problems. The problem is expecting otherwise and thinking that having problems is a problem.

Design is really an act of communication, which means having a deep understanding of the person with whom the designer is communicating.

If the system lets you make the error, it is badly designed. And if the system induces you to make the error, then it is really badly designed.