Progressive disclosure defers advanced or rarely used features to a secondary screen, making applications easier to learn and less error-prone.

To design an easy-to-use interface, pay attention to what users do, not what they say. Self-reported claims are unreliable, as are user speculations about future behavior.

On the Internet, it's survival of the easiest.... Give users a good experience and they're apt to turn into frequent and loyal customers. But ... it's easy to turn to another supplier in the face of even a minor hiccup. Only if a site is extremely easy to use will anybody bother staying around.

People have to want to change before there's any chance of helping them do so.

Users spend most of their time on other sites. This means that users prefer your site to work the same way as all the other sites they already know.

Ultimately, users visit your website for its content. Everything else is just the backdrop.

Users are not designers.